Power Supply Board For FREE

Why would you want to reverse bias a tantalum cap??? mike

Where did I do That? I don't see it.

Gary

Nor do I. I would like to see a few 0.1uF cap's at input and output of the reg IC's though.

Cheers.

Ken

Hi Ken, I tend to use 1 uF tantalums as I have thousands of them and find they work quite well. But if you wish to Substitute .1 uF caps in place of some or all of them, they will work as well, Maybe better in RF Situations.

There are Improvements that can be made, but This is definately close to a Minimum Parts count for a supply that is both current and voltage regulated as well as the ability to go down to Zero volts. Great for the Beginner.

This design is not totally unique, but better than most I have seen on the net.

My hope is it is Cost Effective and Useful to some of these persons.

Take care.......Gary Take care.........Gary

This group seems to like "where's waldo" types of exercises.

If nobody else finds it, I'll post what I think. Maybe I'm wrong...

Hint: There are only four places to look. How hard can that be? ;-)

Just curious about the current limit behavior. I'm kinda worried about what happens when the input voltage to the second IC drops below what it takes to make the chip work. How's the transient response in and out of current limit? Try a plethora of load lines and rep rates on your transient generator. mike

Take a look at what happens when your variable resistor is set to 0.

In order for the output to get to 0 V the adj lead must be -1.25 V with respect to ground. This reverse biases the cap on the adj lead. Use a ceramic here.

Ryan

go

good

the

I'm seeing double today! :-)

Check the spec's for the beast - you should use 0.1's as well as a tantalum. Nice pick-up Mike, I'm flat out reading that late at night, let alone interpreting! :-)

Ken

Ken Taylor wrote: [snip]

Looks to me as if the 1 uF tantalum from the ADJ terminal to ground is seeing anything from the max V minus 1.2V, all the way down to neg 1.2V. So this cap had better be non-polarized.

OK, I see, but after 2 days it didn't affect it and a good portion of the time it was at zero. In any case, that tantalum, or all of them can be replaced with .1 uF caps.

Gary