What kind of transistor turns on with 0.2 volts?
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ margin-bottom:0;
}
$begingroup$
I need a circuit to turn on a LED with 0.2 volts.
I want to do it with a transistor as a switch.
What kind of transistor will turn on at this voltage?
transistors mosfet bjt jfet
asked yesterday
seyyedali hosseiniseyyedali hosseini
172
New contributor
seyyedali hosseini is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
|
show 2 more comments
$begingroup$
I need a circuit to turn on a LED with 0.2 volts.
I want to do it with a transistor as a switch.
What kind of transistor will turn on at this voltage?
transistors mosfet bjt jfet
asked yesterday
seyyedali hosseiniseyyedali hosseini
172
New contributor
seyyedali hosseini is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
5
$begingroup$
Pretty much none of them. I would recommend amplifying the signal before trying to use it as a switch, perhaps with a comparator.
$endgroup$
– Hearth
yesterday
6
$begingroup$
Instead of asking about a transistor which needs to turn on with only 0.2 V (there aren't any but please prove me wrong!) and assume that you can do this with only one transistor (you can't but I'd like to be proven wrong again), describe what your requirements are and ask what solutions exist. A LED will not light up with 0.2 V so there must be some other voltage present. Why 0.2 V? Do research on similar setups (switching LEDs) and learn how that's done.
$endgroup$
– Bimpelrekkie
yesterday
2
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
yesterday
$begingroup$
0.2V isn't enough to run an LED; if you have a rail that'll drive an LED then you can use a comparator.
$endgroup$
– TimWescott
yesterday
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
yesterday
|
show 2 more comments
$begingroup$
I need a circuit to turn on a LED with 0.2 volts.
I want to do it with a transistor as a switch.
What kind of transistor will turn on at this voltage?
transistors mosfet bjt jfet
asked yesterday
seyyedali hosseiniseyyedali hosseini
172
New contributor
seyyedali hosseini is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
I need a circuit to turn on a LED with 0.2 volts.
I want to do it with a transistor as a switch.
What kind of transistor will turn on at this voltage?
transistors mosfet bjt jfet
transistors mosfet bjt jfet
asked yesterday
seyyedali hosseiniseyyedali hosseini
172
New contributor
seyyedali hosseini is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked yesterday
seyyedali hosseiniseyyedali hosseini
172
New contributor
seyyedali hosseini is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked yesterday
seyyedali hosseiniseyyedali hosseini
172
New contributor
seyyedali hosseini is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked yesterday
seyyedali hosseiniseyyedali hosseini
172
asked yesterday
seyyedali hosseiniseyyedali hosseini
172
172
New contributor
seyyedali hosseini is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
seyyedali hosseini is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
seyyedali hosseini is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
5
$begingroup$
Pretty much none of them. I would recommend amplifying the signal before trying to use it as a switch, perhaps with a comparator.
$endgroup$
– Hearth
yesterday
6
$begingroup$
Instead of asking about a transistor which needs to turn on with only 0.2 V (there aren't any but please prove me wrong!) and assume that you can do this with only one transistor (you can't but I'd like to be proven wrong again), describe what your requirements are and ask what solutions exist. A LED will not light up with 0.2 V so there must be some other voltage present. Why 0.2 V? Do research on similar setups (switching LEDs) and learn how that's done.
$endgroup$
– Bimpelrekkie
yesterday
2
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
yesterday
$begingroup$
0.2V isn't enough to run an LED; if you have a rail that'll drive an LED then you can use a comparator.
$endgroup$
– TimWescott
yesterday
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
yesterday
|
show 2 more comments
5
$begingroup$
Pretty much none of them. I would recommend amplifying the signal before trying to use it as a switch, perhaps with a comparator.
$endgroup$
– Hearth
yesterday
6
$begingroup$
Instead of asking about a transistor which needs to turn on with only 0.2 V (there aren't any but please prove me wrong!) and assume that you can do this with only one transistor (you can't but I'd like to be proven wrong again), describe what your requirements are and ask what solutions exist. A LED will not light up with 0.2 V so there must be some other voltage present. Why 0.2 V? Do research on similar setups (switching LEDs) and learn how that's done.
$endgroup$
– Bimpelrekkie
yesterday
2
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
yesterday
$begingroup$
0.2V isn't enough to run an LED; if you have a rail that'll drive an LED then you can use a comparator.
$endgroup$
– TimWescott
yesterday
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
yesterday
5
5
$begingroup$
Pretty much none of them. I would recommend amplifying the signal before trying to use it as a switch, perhaps with a comparator.
$endgroup$
– Hearth
yesterday
$begingroup$
Pretty much none of them. I would recommend amplifying the signal before trying to use it as a switch, perhaps with a comparator.
$endgroup$
– Hearth
yesterday
6
6
$begingroup$
Instead of asking about a transistor which needs to turn on with only 0.2 V (there aren't any but please prove me wrong!) and assume that you can do this with only one transistor (you can't but I'd like to be proven wrong again), describe what your requirements are and ask what solutions exist. A LED will not light up with 0.2 V so there must be some other voltage present. Why 0.2 V? Do research on similar setups (switching LEDs) and learn how that's done.
$endgroup$
– Bimpelrekkie
yesterday
$begingroup$
Instead of asking about a transistor which needs to turn on with only 0.2 V (there aren't any but please prove me wrong!) and assume that you can do this with only one transistor (you can't but I'd like to be proven wrong again), describe what your requirements are and ask what solutions exist. A LED will not light up with 0.2 V so there must be some other voltage present. Why 0.2 V? Do research on similar setups (switching LEDs) and learn how that's done.
$endgroup$
– Bimpelrekkie
yesterday
2
2
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
yesterday
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
yesterday
$begingroup$
0.2V isn't enough to run an LED; if you have a rail that'll drive an LED then you can use a comparator.
$endgroup$
– TimWescott
yesterday
$begingroup$
0.2V isn't enough to run an LED; if you have a rail that'll drive an LED then you can use a comparator.
$endgroup$
– TimWescott
yesterday
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
yesterday
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
yesterday
|
show 2 more comments
4 Answers
4
active
oldest
votes
$begingroup$
Whilst I'm inclined to agree with @Bimpelrekkie that this is probably an X-Y problem, for those who might actually need such a device there are some options. Most MOSFETs are sold as enhancement or depletion mode (less commonly) devices, however it's possible to tune the threshold voltage to approximately zero +/- tens of mV.
For example, the Advanced Linear Devices ALD110800A and similar devices in that series have a nominal zero gate threshold (1uA Ids). The subthreshold behavior is fairly well documented as well.
For your actual situation, use CrossRoads circuit with just about any single supply op-amp or single-supply comparator. LM358 or LM393 will work fine from a 5V supply.
answered yesterday
Spehro PefhanySpehro Pefhany
213k5162432
$endgroup$
add a comment |
$begingroup$
No single transistor can do what you want. Instead, you need to use multiple transistors. A simple voltage comparator will do what you want:
simulate this circuit – Schematic created using CircuitLab
R2 and R3 set the reference voltage for the base of Q2. As long as the voltage at the base of Q1 is less than Vref, all of the current through R1 will flow through Q2. As soon as the input voltage rises above 0.2V, Q2 will cut off and all of the current will flow through Q1 and the LED instead.
Note that since the emitters of the transistors need to be at a negative voltage, this circuit requires a negative supply. An alternative would be to use an IC comparator — you can find single-supply units that can work with input voltages close to ground.
answered yesterday
Dave Tweed♦Dave Tweed
124k10153267
$endgroup$
1
$begingroup$
You can approach the lower rail by using PNPs 'upside down' and a single supply.
$endgroup$
– Russell McMahon
yesterday
$begingroup$
@RussellMcMahon: But then there's no overhead left for the load (LED), at least, not without adding additional transistors. At that point, just get the IC comparator, which is essentially the same thing.
$endgroup$
– Dave Tweed♦
yesterday
$begingroup$
This circuit really needs some positive feedback to achieve a clean switch.
$endgroup$
– EinarA
21 hours ago
add a comment |
$begingroup$
simulate this circuit – Schematic created using CircuitLab
You could also use an Op Amp, or a Comparator. Set one input to 0.2V, when the other input exceeds that, the output will switch.
Here's one example
https://datasheets.maximintegrated.com/en/ds/MAX9107-MAX9109.pdf
edited yesterday
Dave Tweed♦
124k10153267
answered yesterday
CrossRoadsCrossRoads
2,12728
$endgroup$
add a comment |
$begingroup$
A well chosen germanium transistor can do this. I have some that switch at .15V. Finding one might be a problem ; I am not offering any of mine, but they still exist. If you need accurateness use one of the other answers, The simplest solution is to prebias a transistor so the base receives enough voltage to turn on when the input is .2V. I have used this trick in non-critical situations.
answered yesterday
EinarAEinarA
1525
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
});
});
}, "mathjax-editing");
StackExchange.ifUsing("editor", function () {
return StackExchange.using("schematics", function () {
StackExchange.schematics.init();
});
}, "cicuitlab");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "135"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
seyyedali hosseini is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f431394%2fwhat-kind-of-transistor-turns-on-with-0-2-volts%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Whilst I'm inclined to agree with @Bimpelrekkie that this is probably an X-Y problem, for those who might actually need such a device there are some options. Most MOSFETs are sold as enhancement or depletion mode (less commonly) devices, however it's possible to tune the threshold voltage to approximately zero +/- tens of mV.
For example, the Advanced Linear Devices ALD110800A and similar devices in that series have a nominal zero gate threshold (1uA Ids). The subthreshold behavior is fairly well documented as well.
For your actual situation, use CrossRoads circuit with just about any single supply op-amp or single-supply comparator. LM358 or LM393 will work fine from a 5V supply.
answered yesterday
Spehro PefhanySpehro Pefhany
213k5162432
$endgroup$
add a comment |
$begingroup$
Whilst I'm inclined to agree with @Bimpelrekkie that this is probably an X-Y problem, for those who might actually need such a device there are some options. Most MOSFETs are sold as enhancement or depletion mode (less commonly) devices, however it's possible to tune the threshold voltage to approximately zero +/- tens of mV.
For example, the Advanced Linear Devices ALD110800A and similar devices in that series have a nominal zero gate threshold (1uA Ids). The subthreshold behavior is fairly well documented as well.
For your actual situation, use CrossRoads circuit with just about any single supply op-amp or single-supply comparator. LM358 or LM393 will work fine from a 5V supply.
answered yesterday
Spehro PefhanySpehro Pefhany
213k5162432
$endgroup$
add a comment |
$begingroup$
Whilst I'm inclined to agree with @Bimpelrekkie that this is probably an X-Y problem, for those who might actually need such a device there are some options. Most MOSFETs are sold as enhancement or depletion mode (less commonly) devices, however it's possible to tune the threshold voltage to approximately zero +/- tens of mV.
For example, the Advanced Linear Devices ALD110800A and similar devices in that series have a nominal zero gate threshold (1uA Ids). The subthreshold behavior is fairly well documented as well.
For your actual situation, use CrossRoads circuit with just about any single supply op-amp or single-supply comparator. LM358 or LM393 will work fine from a 5V supply.
answered yesterday
Spehro PefhanySpehro Pefhany
213k5162432
$endgroup$
Whilst I'm inclined to agree with @Bimpelrekkie that this is probably an X-Y problem, for those who might actually need such a device there are some options. Most MOSFETs are sold as enhancement or depletion mode (less commonly) devices, however it's possible to tune the threshold voltage to approximately zero +/- tens of mV.
For example, the Advanced Linear Devices ALD110800A and similar devices in that series have a nominal zero gate threshold (1uA Ids). The subthreshold behavior is fairly well documented as well.
For your actual situation, use CrossRoads circuit with just about any single supply op-amp or single-supply comparator. LM358 or LM393 will work fine from a 5V supply.
answered yesterday
Spehro PefhanySpehro Pefhany
213k5162432
edited yesterday
answered yesterday
Spehro PefhanySpehro Pefhany
213k5162432
answered yesterday
Spehro PefhanySpehro Pefhany
213k5162432
answered yesterday
Spehro PefhanySpehro Pefhany
213k5162432
213k5162432
add a comment |
add a comment |
$begingroup$
No single transistor can do what you want. Instead, you need to use multiple transistors. A simple voltage comparator will do what you want:
simulate this circuit – Schematic created using CircuitLab
R2 and R3 set the reference voltage for the base of Q2. As long as the voltage at the base of Q1 is less than Vref, all of the current through R1 will flow through Q2. As soon as the input voltage rises above 0.2V, Q2 will cut off and all of the current will flow through Q1 and the LED instead.
Note that since the emitters of the transistors need to be at a negative voltage, this circuit requires a negative supply. An alternative would be to use an IC comparator — you can find single-supply units that can work with input voltages close to ground.
answered yesterday
Dave Tweed♦Dave Tweed
124k10153267
$endgroup$
1
$begingroup$
You can approach the lower rail by using PNPs 'upside down' and a single supply.
$endgroup$
– Russell McMahon
yesterday
$begingroup$
@RussellMcMahon: But then there's no overhead left for the load (LED), at least, not without adding additional transistors. At that point, just get the IC comparator, which is essentially the same thing.
$endgroup$
– Dave Tweed♦
yesterday
$begingroup$
This circuit really needs some positive feedback to achieve a clean switch.
$endgroup$
– EinarA
21 hours ago
add a comment |
$begingroup$
No single transistor can do what you want. Instead, you need to use multiple transistors. A simple voltage comparator will do what you want:
simulate this circuit – Schematic created using CircuitLab
R2 and R3 set the reference voltage for the base of Q2. As long as the voltage at the base of Q1 is less than Vref, all of the current through R1 will flow through Q2. As soon as the input voltage rises above 0.2V, Q2 will cut off and all of the current will flow through Q1 and the LED instead.
Note that since the emitters of the transistors need to be at a negative voltage, this circuit requires a negative supply. An alternative would be to use an IC comparator — you can find single-supply units that can work with input voltages close to ground.
answered yesterday
Dave Tweed♦Dave Tweed
124k10153267
$endgroup$
1
$begingroup$
You can approach the lower rail by using PNPs 'upside down' and a single supply.
$endgroup$
– Russell McMahon
yesterday
$begingroup$
@RussellMcMahon: But then there's no overhead left for the load (LED), at least, not without adding additional transistors. At that point, just get the IC comparator, which is essentially the same thing.
$endgroup$
– Dave Tweed♦
yesterday
$begingroup$
This circuit really needs some positive feedback to achieve a clean switch.
$endgroup$
– EinarA
21 hours ago
add a comment |
$begingroup$
No single transistor can do what you want. Instead, you need to use multiple transistors. A simple voltage comparator will do what you want:
simulate this circuit – Schematic created using CircuitLab
R2 and R3 set the reference voltage for the base of Q2. As long as the voltage at the base of Q1 is less than Vref, all of the current through R1 will flow through Q2. As soon as the input voltage rises above 0.2V, Q2 will cut off and all of the current will flow through Q1 and the LED instead.
Note that since the emitters of the transistors need to be at a negative voltage, this circuit requires a negative supply. An alternative would be to use an IC comparator — you can find single-supply units that can work with input voltages close to ground.
answered yesterday
Dave Tweed♦Dave Tweed
124k10153267
$endgroup$
No single transistor can do what you want. Instead, you need to use multiple transistors. A simple voltage comparator will do what you want:
simulate this circuit – Schematic created using CircuitLab
R2 and R3 set the reference voltage for the base of Q2. As long as the voltage at the base of Q1 is less than Vref, all of the current through R1 will flow through Q2. As soon as the input voltage rises above 0.2V, Q2 will cut off and all of the current will flow through Q1 and the LED instead.
Note that since the emitters of the transistors need to be at a negative voltage, this circuit requires a negative supply. An alternative would be to use an IC comparator — you can find single-supply units that can work with input voltages close to ground.
answered yesterday
Dave Tweed♦Dave Tweed
124k10153267
answered yesterday
Dave Tweed♦Dave Tweed
124k10153267
answered yesterday
Dave Tweed♦Dave Tweed
124k10153267
answered yesterday
Dave Tweed♦Dave Tweed
124k10153267
124k10153267
1
$begingroup$
You can approach the lower rail by using PNPs 'upside down' and a single supply.
$endgroup$
– Russell McMahon
yesterday
$begingroup$
@RussellMcMahon: But then there's no overhead left for the load (LED), at least, not without adding additional transistors. At that point, just get the IC comparator, which is essentially the same thing.
$endgroup$
– Dave Tweed♦
yesterday
$begingroup$
This circuit really needs some positive feedback to achieve a clean switch.
$endgroup$
– EinarA
21 hours ago
add a comment |
1
$begingroup$
You can approach the lower rail by using PNPs 'upside down' and a single supply.
$endgroup$
– Russell McMahon
yesterday
$begingroup$
@RussellMcMahon: But then there's no overhead left for the load (LED), at least, not without adding additional transistors. At that point, just get the IC comparator, which is essentially the same thing.
$endgroup$
– Dave Tweed♦
yesterday
$begingroup$
This circuit really needs some positive feedback to achieve a clean switch.
$endgroup$
– EinarA
21 hours ago
1
1
$begingroup$
You can approach the lower rail by using PNPs 'upside down' and a single supply.
$endgroup$
– Russell McMahon
yesterday
$begingroup$
You can approach the lower rail by using PNPs 'upside down' and a single supply.
$endgroup$
– Russell McMahon
yesterday
$begingroup$
@RussellMcMahon: But then there's no overhead left for the load (LED), at least, not without adding additional transistors. At that point, just get the IC comparator, which is essentially the same thing.
$endgroup$
– Dave Tweed♦
yesterday
$begingroup$
@RussellMcMahon: But then there's no overhead left for the load (LED), at least, not without adding additional transistors. At that point, just get the IC comparator, which is essentially the same thing.
$endgroup$
– Dave Tweed♦
yesterday
$begingroup$
This circuit really needs some positive feedback to achieve a clean switch.
$endgroup$
– EinarA
21 hours ago
$begingroup$
This circuit really needs some positive feedback to achieve a clean switch.
$endgroup$
– EinarA
21 hours ago
add a comment |
$begingroup$
simulate this circuit – Schematic created using CircuitLab
You could also use an Op Amp, or a Comparator. Set one input to 0.2V, when the other input exceeds that, the output will switch.
Here's one example
https://datasheets.maximintegrated.com/en/ds/MAX9107-MAX9109.pdf
edited yesterday
Dave Tweed♦
124k10153267
answered yesterday
CrossRoadsCrossRoads
2,12728
$endgroup$
add a comment |
$begingroup$
simulate this circuit – Schematic created using CircuitLab
You could also use an Op Amp, or a Comparator. Set one input to 0.2V, when the other input exceeds that, the output will switch.
Here's one example
https://datasheets.maximintegrated.com/en/ds/MAX9107-MAX9109.pdf
edited yesterday
Dave Tweed♦
124k10153267
answered yesterday
CrossRoadsCrossRoads
2,12728
$endgroup$
add a comment |
$begingroup$
simulate this circuit – Schematic created using CircuitLab
You could also use an Op Amp, or a Comparator. Set one input to 0.2V, when the other input exceeds that, the output will switch.
Here's one example
https://datasheets.maximintegrated.com/en/ds/MAX9107-MAX9109.pdf
edited yesterday
Dave Tweed♦
124k10153267
answered yesterday
CrossRoadsCrossRoads
2,12728
$endgroup$
simulate this circuit – Schematic created using CircuitLab
You could also use an Op Amp, or a Comparator. Set one input to 0.2V, when the other input exceeds that, the output will switch.
Here's one example
https://datasheets.maximintegrated.com/en/ds/MAX9107-MAX9109.pdf
edited yesterday
Dave Tweed♦
124k10153267
answered yesterday
CrossRoadsCrossRoads
2,12728
edited yesterday
Dave Tweed♦
124k10153267
edited yesterday
Dave Tweed♦
124k10153267
edited yesterday
Dave Tweed♦
124k10153267
124k10153267
answered yesterday
CrossRoadsCrossRoads
2,12728
answered yesterday
CrossRoadsCrossRoads
2,12728
answered yesterday
CrossRoadsCrossRoads
2,12728
2,12728
add a comment |
add a comment |
$begingroup$
A well chosen germanium transistor can do this. I have some that switch at .15V. Finding one might be a problem ; I am not offering any of mine, but they still exist. If you need accurateness use one of the other answers, The simplest solution is to prebias a transistor so the base receives enough voltage to turn on when the input is .2V. I have used this trick in non-critical situations.
answered yesterday
EinarAEinarA
1525
$endgroup$
add a comment |
$begingroup$
A well chosen germanium transistor can do this. I have some that switch at .15V. Finding one might be a problem ; I am not offering any of mine, but they still exist. If you need accurateness use one of the other answers, The simplest solution is to prebias a transistor so the base receives enough voltage to turn on when the input is .2V. I have used this trick in non-critical situations.
answered yesterday
EinarAEinarA
1525
$endgroup$
add a comment |
$begingroup$
A well chosen germanium transistor can do this. I have some that switch at .15V. Finding one might be a problem ; I am not offering any of mine, but they still exist. If you need accurateness use one of the other answers, The simplest solution is to prebias a transistor so the base receives enough voltage to turn on when the input is .2V. I have used this trick in non-critical situations.
answered yesterday
EinarAEinarA
1525
$endgroup$
A well chosen germanium transistor can do this. I have some that switch at .15V. Finding one might be a problem ; I am not offering any of mine, but they still exist. If you need accurateness use one of the other answers, The simplest solution is to prebias a transistor so the base receives enough voltage to turn on when the input is .2V. I have used this trick in non-critical situations.
answered yesterday
EinarAEinarA
1525
answered yesterday
EinarAEinarA
1525
answered yesterday
EinarAEinarA
1525
answered yesterday
EinarAEinarA
1525
1525
add a comment |
add a comment |
seyyedali hosseini is a new contributor. Be nice, and check out our Code of Conduct.
seyyedali hosseini is a new contributor. Be nice, and check out our Code of Conduct.
seyyedali hosseini is a new contributor. Be nice, and check out our Code of Conduct.
seyyedali hosseini is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Electrical Engineering Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f431394%2fwhat-kind-of-transistor-turns-on-with-0-2-volts%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
5
$begingroup$
Pretty much none of them. I would recommend amplifying the signal before trying to use it as a switch, perhaps with a comparator.
$endgroup$
– Hearth
yesterday
6
$begingroup$
Instead of asking about a transistor which needs to turn on with only 0.2 V (there aren't any but please prove me wrong!) and assume that you can do this with only one transistor (you can't but I'd like to be proven wrong again), describe what your requirements are and ask what solutions exist. A LED will not light up with 0.2 V so there must be some other voltage present. Why 0.2 V? Do research on similar setups (switching LEDs) and learn how that's done.
$endgroup$
– Bimpelrekkie
yesterday
2
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
yesterday
$begingroup$
0.2V isn't enough to run an LED; if you have a rail that'll drive an LED then you can use a comparator.
$endgroup$
– TimWescott
yesterday
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
yesterday