simple_delay

[ersa6]

Can I use this circuit as simple delay circuit for relay and can I change specified transistors with ordinary like bc550/546/2N5551 etc...And what components should I change except capacitor lets say that delay would be 3 sec. I would put there 47uF is that OK?

Thanks

 

[CBS240]

What is the purpose? and if it is to delay turn on, what about turn off delay?

 

[ersa6]

What is the purpose? and if it is to delay turn on, what about turn off delay?

The purpose is bypassing NTC thermistor, after lets say 3sec or more, wail the power supply charges capacitors

 

[dangus]

I think the first transistor is being used as a zener, so any substitution would have to take the zener characteristic into account. Maybe it's better to use a 555, or an op-amp or comparator with hysteresis.

 

[ersa6]

I think the first transistor is being used as a zener, so any substitution would have to take the zener characteristic into account. Maybe it's better to use a 555, or an op-amp or comparator with hysteresis.

I found all answers on this page
http://www.bowdenshobbycircuits.info/page2.htm