# 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
9,912
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.