Electro Tech forum,
I posted about my 555 timer problem in "555 frequency problem"
and thought I had fixed when I changed to a TLC555. Not so.
The 555 frequency is alright but I'm still having power
supply problems.
I think my basic hookup must be wrong.
As I stated in my previous post I'm using a 110 to 9 vac
transformer feeding a BR805D full wave bridge and an LM7805C
regulator. Without the regulator hooked up I read 10.47 vac
on the ac pins of the bridge and 4.40 ac volts or 9.05 dc
volts on the other 2 pins.
As soon as I connect the + pin of the bridge to the input pin
of the regulator the dc voltage coming out of the bridge drops
to 8.38. There is a 220uf cap on the input pin of the regulator
and a 10uf on the output pin. The output pin of the regulator
reads only 4.46 volts.
I'm mostly a software guy trying to learn hardware so any help
would be appreciated. I would post the circuit if I knew how.
Thanks,
jerryd
I posted about my 555 timer problem in "555 frequency problem"
and thought I had fixed when I changed to a TLC555. Not so.
The 555 frequency is alright but I'm still having power
supply problems.
I think my basic hookup must be wrong.
As I stated in my previous post I'm using a 110 to 9 vac
transformer feeding a BR805D full wave bridge and an LM7805C
regulator. Without the regulator hooked up I read 10.47 vac
on the ac pins of the bridge and 4.40 ac volts or 9.05 dc
volts on the other 2 pins.
As soon as I connect the + pin of the bridge to the input pin
of the regulator the dc voltage coming out of the bridge drops
to 8.38. There is a 220uf cap on the input pin of the regulator
and a 10uf on the output pin. The output pin of the regulator
reads only 4.46 volts.
I'm mostly a software guy trying to learn hardware so any help
would be appreciated. I would post the circuit if I knew how.
Thanks,
jerryd