Hello. I am using this for my preamp heater circuit:
I also connect that the output to an LM555 timer that activates a relay and all sort of jazz.
the thing is that i get some mishaviours because of this turn on noise:
if I switch it off and turn on again, looks like this, and everything works flawlessly:
any idea on how to reduce that noise?
is this because of the voltage doubler?
the diodes inside the BR310?
may be transformer inrush current?
THANK YOU!
I also connect that the output to an LM555 timer that activates a relay and all sort of jazz.
the thing is that i get some mishaviours because of this turn on noise:
if I switch it off and turn on again, looks like this, and everything works flawlessly:
any idea on how to reduce that noise?
is this because of the voltage doubler?
the diodes inside the BR310?
may be transformer inrush current?
THANK YOU!
Are you on 50Hz power? It seems that you have way too much filtering capacitance and it takes 2 seconds to charge the caps. Once they are charged, it looks fine.
yes, 50hz indeed. i dont think the 2 seconds are the problem but the hills and valleys while charging..
You're using a half-wave doubler. Things will probably improve if you reconfigure as a full-wave doubler.
The output from the regulator will pass all the incoming ripple until the regulators specified minimum Vin/Vout differential is reached. That will be around 2 to 3 volts at high current. 10,000uF on the output of a reg is not recommended. Try reducing that to around 10uF.
Do you even need a regulator for a 555 and some relays? Maybe simple RC would cause fewer problems 🤷♂️
thinking out loud.. The relay draws 170mA when kicks in.
I will have to take that into consideration and add an extra resistor to reduce the voltage to 6.3V and bypass it when the relay kicks in..
I will have to take that into consideration and add an extra resistor to reduce the voltage to 6.3V and bypass it when the relay kicks in..
I dont think Im getting you.
If I set the RC filter to get 6.3V when the heater has kicked in.. I would have >6.5V when the relay hasnt kicked in yet..
Thats why I said I had to add an extra resistor for that lapse of time.. to keep the heater voltage at 6.3v during warm up.
Unless having it in 6.5V for one minute isn't harmful?
If I set the RC filter to get 6.3V when the heater has kicked in.. I would have >6.5V when the relay hasnt kicked in yet..
Thats why I said I had to add an extra resistor for that lapse of time.. to keep the heater voltage at 6.3v during warm up.
Unless having it in 6.5V for one minute isn't harmful?
Hello. I wanted to report back on this issue I had.
I finally replaced the regulator with a couple of wirewound resistors. Much less heat (the LM338 needs Vin-Vout > 3V) and the transformer load is lower than before.
But the problem I had was fixed by increasing the capacitor in trigger section of the LM555 from 0.22uF to 10uF.
May be an 1uF capacitor would have been enough though.
Thanks for all the suggestions.
Cheers.
I finally replaced the regulator with a couple of wirewound resistors. Much less heat (the LM338 needs Vin-Vout > 3V) and the transformer load is lower than before.
But the problem I had was fixed by increasing the capacitor in trigger section of the LM555 from 0.22uF to 10uF.
May be an 1uF capacitor would have been enough though.
Thanks for all the suggestions.
Cheers.