Does this DC regulator work with AC??

[paul.1911]

Hello,
I'm numb in electric stuffs, so please excuse that,
I just wanna know if this circuit can accept AC power instead of DC??

**broken link removed**

If not, can you please modify it for me?

I want 15v out, so will change that 12v zener to 15.

 

[tcmtech]

No it cant and neither can it be easily modified to work on AC either.

 

[picbits]

Well if you put a bridge rectifier before the left 100uF capacitor and increased that capacitor to 2200uf or higher then yes it would work but would still give you a DC output.

 

[jpanhalt]

That is a 12.7V zener to give 12V out; so, you need a 15.7V for 15V to account for the usual 0.7V BE differential to turn the transistor on. See here: https://en.wikipedia.org/wiki/Current_source

John

 

[paul.1911]

well thanks all for their inputs

Well if you put a bridge rectifier before the left 100uF capacitor and increased that capacitor to 2200uf or higher then yes it would work but would still give you a DC output.

Why bridge? Why not a single diode would work?
Actually in my bike the AC connectors runs a 35w bulb on AC and that alternator is not even powerful enough to handle 55w, tried everything didn't work. It hardly produce 3 or 3.1 Amps from 0-30VAC
So, I wanna give a try 45w bulb. But the built in regulator stops the volts exceeding at 12v.

So, I need something 15v output thats 15x3=45w. No matter whether out is AC or DC. I only want to power the bulb.

That is like this



Only that single wire is connected to the regulator, if i remove it, it would have no control over the bulb.

So does a single diode will work?
I've 6A4 6 Amp diode. will put just before the input, then would i still need to change that left 100uf capacitor to 2200uf??
I've one 4700uf 35v.

I wish if this work!

Edit:
I also tried this method to increase 2v https://mastercircuits.blogspot.in/2011/08/headlight-intensity-enhancer.html
But volts exceeded to 20 and my bulb got blow.

That is a 12.7V zener to give 12V out; so, you need a 15.7V for 15V to account for the usual 0.7V BE differential to turn the transistor on. See here: https://en.wikipedia.org/wiki/Current_source

John

Thanks John
The link u provided has crossover my head

 

[picbits]

well thanks all for their inputs



Why bridge? Why not a single diode would work?

You don't want to lose half your voltage by just rectifying half the wave - it sounds like you want as much power as possible

 

[MikeMl]

Previous forum thread about shunt regulator for motorcycle

Another

(You will have to wait until the site manager restores the figures to see the circuit diagrams)

 

[paul.1911]

@picbits & MikeMI

okay then that circuit will not work
but i found another one, and i think this will surely work **broken link removed**
Just need some change and it will be set perfect.

 

[dr pepper]

Looks as though it'd do it.
Note that if your alty is much bigger than what the reg is designed for it'll get fried.
For Q4 you could use a Tip 3055 rather than a 2n3055, the tip(sometimes called 2n3055P) is much easier to fasten to a heatsink, and its the same device.