Transistor based traffic lights

I

Ibetcha0045

New Member

• Jan 16, 2011

• #1

I have tried to make a two sided traffic light using trasistors. I know that I could do it with ic's but I really want one the is analog.

 

blueroomelectronics

Well-Known Member

• Jan 16, 2011

• #2

You'll need more than transistors.

 

MikeMl

Well-Known Member

Most Helpful Member

• Jan 16, 2011

• #3

Do you mean like flip-flops and logic gates made out of transistors?

 

audioguru

Well-Known Member

Most Helpful Member

• Jan 16, 2011

• #4

You could make a timer from a big capacitor charging from a high value resistor and a Fet or Darlington sensing its output voltage.
Then instead of using an inexpensive counter IC you can make your own from about 30 transistors.

 

Mosaic

Well-Known Member

• Jan 16, 2011

• #5

Perhaps the circuit at the bottom of the link could work:
Telephone In-Use Relay, LM317 Regulators, Lithium Charger

Adjust the RC combos to control the red/green light delays, replace the LEDs with DPDT relays to control two sets of red/green lights at an intersection. Wire the relays so green on one light means red on the other.