astable

[sb****33]

Hi

I wanted a circuit with a timer controlling an output preamp relay. A LED should blinking meanwhile and stay ON when the relay
get closed.*
I designed this with RL3 reseting U4. Q41 also starts RL2 the output relay.
It works but , sometimes, after a while, D7 restart blinking. Maybe there is not enough current for 2 relays.
How can I fix this ?
Mainly, is there a more clever way to achieve the goal ?

 

[jwilhelm]

A really simple way is to control it with an Arduino.

 

[rayma]

I wanted a circuit with a timer controlling an output preamp relay. A LED should blinking meanwhile
and stay ON when the relay get closed. is there a more clever way to achieve the goal ?

I designed an output muting circuit with a bicolor led, red when muted and green when enabled.
It's just a DPDT relay, LM555, a 2N2222, the led, and a few passive parts. If you're interested,
I'll get the schematic to you. (No Arduino required.)

 

[tauro0221]

Hi,
I agreed 100% with jwilhelm. You can use the Arduino Nano. Cost $5.0. Simple solution.

 

[sb****33]

I designed an output muting circuit with a bicolor led, red when muted and green when enabled.
It's just a DPDT relay, LM555, a 2N2222, the led, and a few passive parts. If you're interested,
I'll get the schematic to you. (No Arduino required.)

Arduino is just too sophisticated this situation, I'm interested with your design. Thanks.

 

[rayma]

Arduino is just too sophisticated this situation, I'm interested with your design. Thanks.

Ok, I'll dig it out of my file and email it to you. It was designed to run off the 12VDC filament supply
in a tube preamp, muting for 30 seconds after power on. The low-leakage LM555 timing capacitor
can be changed to a smaller value for less delay.

 

[Mooly]

Quick thoughts on your original circuit in post #1

If the collectors fall to near zero when on, then there is no problem with being able to drive two relays.

Cap on pin 5 is way to big. Typically its around 0.1uf

Pin 4 shouldn't be able to float, its needs a pull up to + supply of say 3k3.

If using an original type 555 chip then a 100uf cap should be across pins 8 and 1.

 

[sb****33]

Ok, I'll dig it out of my file and email it to you. It was designed to run off the 12VDC filament supply
in a tube preamp, muting for 30 seconds after power on. The low-leakage LM555 timing capacitor
can be changed to a smaller value for less delay.

unfortunately, I guess you could not find the schematic. Sorry

 

[rayma]

unfortunately, I guess you could not find the schematic. Sorry

Yes, I have it ready for you. Can you send me your private email address
so I can attach it to my email? I'd rather not post it here. Thanks.

 

[sb****33]

OK, I understand.

[email protected]

Thank's.