Re: How to modify 20V 3.5Am to 13V 1Am

Many thanks

On Fri, 31 Mar 2006 17:29:39 GMT, ehsjr <ehsjr@xxxxxxxxxxxxxxxx>
wrote:

bigdaddy wrote:
I have Dell Model AA20031 Power Supply for Dell Laptop and I like to
reduce it to 13V, 1Am so I can use it on my Canon BJC-250. I have
opened the pack and I like to know how to do it. Thanks

Get the Vellman kit.

If you *must* "roll your own" ...
Here's a "picture".


+-----------------------> Gnd To Canon BJC-250 (-)
|
| -Power Supply+
------ | ---------
+---|2200 R|---+---|-AA20031+|---+
| ------ --------- |
| |
| ------ |
| | o | |
| |______| |
| /______/| |
| | || |
| |LM317 |/ |
| ------ |
| | | | |
+----------+ | +---------------+
| |
| |
| ------ |
+---|240ohm|--+------------------------> 12.7V To Canon BJC-250 +
------

With the 240 and 2200 resistors shown, you'll be within
.3 volts of target (13) per the computation. If you want
to get 13 volts exactly, add a 56 ohm resistor in series
with the 2200 ohm resistor. You do not need any capacitors
as shown on the data*** if you keep the LM317 relatively
close to the power supply. You must mount the LM317 on a
good heatsink.

Ed
.

Quantcast