Transistor doesnt work?

Vaarna

Joined Nov 17, 2015
3
I have a simple circuit with 2 transistors making an and gate and switches to turn on the transistors and a led to light up when the 2 switches are on, but
it doesnt work the transistors just heat up.

ps.sorry if im noob

mcgyvr

Joined Oct 15, 2009
5,394
post a schematic..... noob

A schematic will show all the details your words left out.

GopherT

Joined Nov 23, 2012
8,012
I have a simple circuit with 2 transistors making an and gate and switches to turn on the transistors and a led to light up when the 2 switches are on, but
it doesnt work the transistors just heat up.

ps.sorry if i`m noob
Post a close-up photo of your circuit and a hand drawn (or better) schematic of the circuit. Also include the value of the resistors you used.

Vaarna

Joined Nov 17, 2015
3

GopherT

Joined Nov 23, 2012
8,012
Your transistors have been damaged because you should have a resistor between the (+) and base of the transistor. Look at the datasheet for the transistor and look up the max current into the base.

Dodgydave

Joined Jun 22, 2012
8,671
Yes you have omitted the resistors to the Bases of the transistors, so they will burn up, use any values from 1K to 10K.

GopherT

Joined Nov 23, 2012
8,012

GopherT

Joined Nov 23, 2012
8,012

mcgyvr

Joined Oct 15, 2009
5,394
Don't even need the transistors just put the 2 switches in series.. (or are the switches momentary..even so)

Last edited:

GopherT

Joined Nov 23, 2012
8,012
Don't even need the transistors just put the 2 switches in series.. (or are the switches momentary..even so)
I think he is experimenting - making an AND logic gate.