Good ol 3055 transistor found and Astron and Duracomm systems.
Use a LM723 and a few other components. The one in question would be the
output resistor at 5W .33Ohm
I have built several of these to regulate 12-18vs seamlessly to our
mikrotik routers to help with smoothing out the
raw dc from the duracomm systems at 24v-48v out.
Our mikrotiks seem to have fewer issues related to power and reboots.
Went the whole last year without a single reboot on the network.
On 12/31/2014 04:59 PM, Forrest Christian (List Account) via Af wrote:
The electronic way is a constant current source shunted to ground or
through a resistor bank.
One hefty npn power transistor and a few smallish components. Or a
jfet with source tied to gate, with a current adjustment resistor in
the source lead. Or any of a hundred circuits.
For more wattage you can parallel several, each adjusted to take their
fraction of the total amps.
I seem to be slowly turning into a power electronics engineer over here.
On Dec 31, 2014 3:42 PM, "chuck--- via Af" <[email protected]
<mailto:[email protected]>> wrote:
I am thinking a DC-DC converter that will take a wide input and
constant voltage output into a nice temperature compensated
resistive load. What voltage range do you want?
Doh!, that would be a constant power load.
You want constant current load. Have to continue thinking...
*From:* [email protected] <mailto:[email protected]>
*Sent:* Wednesday, December 31, 2014 3:39 PM
*To:* [email protected] <mailto:[email protected]>
*Subject:* Re: [AFMUG] Dc electric load ? Chuck ?
I know how to do it really cheap and easy under 2 amps. Have to
think on this a bit. I have used hot water heating elements and
coils of wire (in a bucket of water) for high wattage resistors
but obviously not constant current.
*From:* TJ Trout via Af <mailto:[email protected]>
*Sent:* Wednesday, December 31, 2014 12:11 PM
*To:* [email protected] <mailto:[email protected]>
*Subject:* [AFMUG] Dc electric load ? Chuck ?
Anyone know of a inexpensive do it yourself way to make a dc
constant current electric load for testing power supplies, lithium
batteries , etc ? Looking for something maybe 2kw+ and the
cheapest premade thing I can find is $3500. Maybe I'll just use a
carbon pile load but that will be much less accurate.
