question about voltage regulators

[Sensei Tim]

So i'm working on a project that was inspired by Zach's mini amp and Kinski's power amp discovery.

I want to use a standard 9V power supply and then use the 25V charge pump layout into an L78M24 24V voltage regulator to drive the power amp.

My question is for the L78M - the app notes show a DC Parameter example circuit that has a 330n cap between input and ground and a 100n cap between output and ground.  Do i need to add these caps or can i just take the 25V output from the charge pump and connect it to the input of the L78M and get the 24V output?

datasheet/application notes;  http://www.mouser.com/ds/2/389/l78m-974157.pdf


Thanks

T

[rocket88]

I would suggest against that idea for one big reason, you're not going to get enough amperage. I believe you also want to have a larger difference between the incoming voltage to the regulator, and what you want the output voltage to be. I would also use an LM338 regulator which is variable so you've got a lot of options.

If you're looking at doing something similar to what I did shoot me an email and I'll let you know exactly what I did and help you out.

[Sensei Tim]

i really didn't want to have to use an AC-DC transformer, but i guess i might not have a choice lol.

email coming your way..

[Travis]

Yeah I tried to power my amp board with a charge pump just to see if it's possible and not only did it not work but I think it broke the charge pump haha

If you are powering the amp and preamp off the same power supply, you could simply buy a regulated power supply that puts out the voltage and current that you need and not use any transformer or regulator or anything

[alltrax74]

If you feed a 7824 with 25v, the voltage drop due to the regulator will give you less than 24v, check the datasheet