Hi,
I'm new to this forum so I thought I'd better say hello before getting down to details... so hi!
I have no qualifications in electronics but I've been tinkering with the subject for a long time, since I got one of those 1001 toy project boards when i was about 10.
The main reason for posting is this....
My dad has this really old model railway controller wich isn't made anymore. I took it apart and looked at the circuit which seemed very simple so I thought I'd have a go at making one myself. I translated the circuit board into a schematic and have now built a working prototype on breadboard. It's just, because of my lack of knowlege in certain areas, I'm not quite sure why some of the components are connected the way they are. So I was wondering if someone might be able to explain it to me.
Anyway, here is the schematic
I understand what each bit of the circuit does, apart from one thing. I'm just not sure why there is a 10uf capacitor (C3) connected between the emitter of Q2 and the base of Q1. It doesn't seem to make any difference to the controller if I leave it out.
If anyone could shed some light on this I'd be very grateful.
Thanks a lot,
John.
I'm new to this forum so I thought I'd better say hello before getting down to details... so hi!
I have no qualifications in electronics but I've been tinkering with the subject for a long time, since I got one of those 1001 toy project boards when i was about 10.
The main reason for posting is this....
My dad has this really old model railway controller wich isn't made anymore. I took it apart and looked at the circuit which seemed very simple so I thought I'd have a go at making one myself. I translated the circuit board into a schematic and have now built a working prototype on breadboard. It's just, because of my lack of knowlege in certain areas, I'm not quite sure why some of the components are connected the way they are. So I was wondering if someone might be able to explain it to me.
Anyway, here is the schematic
I understand what each bit of the circuit does, apart from one thing. I'm just not sure why there is a 10uf capacitor (C3) connected between the emitter of Q2 and the base of Q1. It doesn't seem to make any difference to the controller if I leave it out.
If anyone could shed some light on this I'd be very grateful.
Thanks a lot,
John.