i’m just wondering why my traffic light isn’t changing. i have waited 5 minutes and it hasn’t changed. i had trouble soldering t3, (bridged t3 and r12, pulled of copper totally) could this have been the source?
id appreciate a fast response…
thanks
how is the copper pad fixable, and where might i find a new transistor?
10 min later- soldered r12- t3 together, light changed when i flicked the switch a few times. why is this happening?
For some reason (most likely an assembly problem), the oscillator (T1, T2, T3) is not working. Check your assembly.
yes, i believe that it is a transistor problem with t3, but it is still not working. all other assembly is correct. can i buy 1 more of each transistor? where?
The place that sells kits usually sells parts aswell.
ok, ill check the store. should i keep t3-r12 soldered together?
Hi,
Looking at the schematics it looks like R12 should go to the base of T3
middle one, right??
Yes the middle one.
so ill keep it soldered, but im still having problems with the oscillator(s)
Have you tested the transistors?
If you have a volt meter with a diode setting on it.
You can try the following.
Remove all power
T1 and T2 are NPNs
So if you place the positive lead to the base (middle leg) then take the negative lead and touch either of the outter legs you should read about 500 to 650 ohms
T3 is a PNP
Negative lead to the base (middle leg) then take the positive lead and touch the outer legs you should get around 500 to 650 ohms.
This can work while they are in the circuit but incase you get weird readings you may want to remove it from the board and test again.
Remember this is just a quick test.
I really hope this helps.
I should said that the meter needs to set on the diode setting.
Sorry bout that.
k thank you, ill test it
let you know how it goes