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What kind of transistor turns on with 0.2 volts?
What kind of transistor turns on with 0.2 volts?
Using transistor as switch with low voltageWhat type of transistor would be required?Simple transistor circuit with unconnected gate pin acts strangelyTurn off an always on led with transistorTurning on LED panel with a NPN transistorWhat kind of transistor do I use for switching high voltage with a microcontroller?switch a PN2222 transistor at 18 volts, with variable 0 to 30 volts inputIs there any 'switching IC' to replace 'transistor switch' for switching the 12 volts LED array?What is a 0118 transistor?how to switch dc motor with transistor?Turns 12 volts DC to 60 volts DC with 2mA
.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
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.
$endgroup$
add a comment |
$begingroup$
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
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.
$endgroup$
3
$begingroup$
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
4 hours ago
3
$begingroup$
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
4 hours ago
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
3 hours ago
$begingroup$
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
44 mins ago
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
17 mins ago
add a comment |
$begingroup$
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
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
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.
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 4 hours ago
seyyedali hosseiniseyyedali hosseini
62
62
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.
3
$begingroup$
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
4 hours ago
3
$begingroup$
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
4 hours ago
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
3 hours ago
$begingroup$
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
44 mins ago
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
17 mins ago
add a comment |
3
$begingroup$
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
4 hours ago
3
$begingroup$
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
4 hours ago
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
3 hours ago
$begingroup$
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
44 mins ago
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
17 mins ago
3
3
$begingroup$
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
4 hours ago
$begingroup$
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
4 hours ago
3
3
$begingroup$
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
4 hours ago
$begingroup$
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
4 hours ago
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
3 hours ago
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
3 hours ago
$begingroup$
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
44 mins ago
$begingroup$
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
44 mins ago
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
17 mins ago
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
17 mins ago
add a comment |
3 Answers
3
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.
$endgroup$
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.
$endgroup$
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
$endgroup$
$begingroup$
You should adjust the R2 or R3 to actually put 0.2V on the '+' input -- R3 = 3.9k$Omega$, or R2 = 2.4M$Omega$, if the comparator is up to the task.
$endgroup$
– TimWescott
43 mins ago
add a comment |
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3 Answers
3
active
oldest
votes
3 Answers
3
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.
$endgroup$
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.
$endgroup$
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.
$endgroup$
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.
answered 4 hours ago
Spehro PefhanySpehro Pefhany
213k5162431
213k5162431
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.
$endgroup$
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.
$endgroup$
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.
$endgroup$
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 4 hours ago
Dave Tweed♦Dave Tweed
123k9153267
123k9153267
add a comment |
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
$endgroup$
$begingroup$
You should adjust the R2 or R3 to actually put 0.2V on the '+' input -- R3 = 3.9k$Omega$, or R2 = 2.4M$Omega$, if the comparator is up to the task.
$endgroup$
– TimWescott
43 mins 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
$endgroup$
$begingroup$
You should adjust the R2 or R3 to actually put 0.2V on the '+' input -- R3 = 3.9k$Omega$, or R2 = 2.4M$Omega$, if the comparator is up to the task.
$endgroup$
– TimWescott
43 mins 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
$endgroup$

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
answered 3 hours ago
CrossRoadsCrossRoads
2,08728
2,08728
$begingroup$
You should adjust the R2 or R3 to actually put 0.2V on the '+' input -- R3 = 3.9k$Omega$, or R2 = 2.4M$Omega$, if the comparator is up to the task.
$endgroup$
– TimWescott
43 mins ago
add a comment |
$begingroup$
You should adjust the R2 or R3 to actually put 0.2V on the '+' input -- R3 = 3.9k$Omega$, or R2 = 2.4M$Omega$, if the comparator is up to the task.
$endgroup$
– TimWescott
43 mins ago
$begingroup$
You should adjust the R2 or R3 to actually put 0.2V on the '+' input -- R3 = 3.9k$Omega$, or R2 = 2.4M$Omega$, if the comparator is up to the task.
$endgroup$
– TimWescott
43 mins ago
$begingroup$
You should adjust the R2 or R3 to actually put 0.2V on the '+' input -- R3 = 3.9k$Omega$, or R2 = 2.4M$Omega$, if the comparator is up to the task.
$endgroup$
– TimWescott
43 mins ago
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.
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3
$begingroup$
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
4 hours ago
3
$begingroup$
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
4 hours ago
$begingroup$
Highly related if not duplicate: electronics.stackexchange.com/questions/129183/…
$endgroup$
– winny
3 hours ago
$begingroup$
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
44 mins ago
$begingroup$
What's the LED and what's the current and voltage it requires? What power supply rails do you have?
$endgroup$
– jonk
17 mins ago