Re: Any experience with ELECTRONIC LOADS would be appreciated


ChuckA
 

I bought one of the Chinese programmable loads, what is called a 3700 series. They show up with various names mine was an Array 3710A. Input voltage up to 360V, current up to 30A, power up to 150W, the model 3711A same but power rating is 300W.

Easy to use and has a computer control software that I never tried. It gets a bit noisy when all 3 fans kick in when you are near max power.

Worked very well on the low voltage high current supplies I was building.

Chuck

On 1/25/2018 5:44 PM, Dennis Tillman W7PF wrote:
Hi Stefan.
I was looking for a cheap, no frills, solution I could start using quickly. I don't need another project to design and build.
What I saw on Ebay were a whole bunch of Chinese electronic loads for pocket change that I could put to use right away and when I'm done put them away until the next time I need one.
I can't recall ever needing a test load in the past. Normally I just use a power resistor. When I saw the ones on Ebay at very reasonable prices I thought it might be time to switch from resistors to an electronic load because it looked more flexible.
Dennis
-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of stefan_trethan
Sent: Thursday, January 25, 2018 11:57 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Any experience with ELECTRONIC LOADS would be appreciated
Hi Dennis,
I have not tried the loads on Ebay but use different electronic loads extensively every day.
I have also built several of my own where commercial products did not offer what I needed.
Are you looking at the Chinese loads in a desktop case such as the Maynuo branded one, or something else?
There is information about them here, they are apparently no so bad:
<https://www.eevblog.com/forum/testgear/which-dc-electronic-load-to-get/>
You can make a load fairly easily, I have always used a beefy mosfet on a heatsink, with a shunt resistor in the source lead.
A simple opamp control loop can do constant voltage/current/resistance control.
Whatever you buy or build, always keep in mind that there is a control loop involved. For certain tests a true resistive load is the only way.
ST
On Thu, Jan 25, 2018 at 8:42 PM, Dennis Tillman W7PF <@Dennis_Tillman_W7pF> wrote:
I occasionally have a need for an electronic load. There are many
listed on Ebay. It would appear the Ebay ones are variations on about
10 different designs. Has anyone bought an electronic load off of
Ebay? If so what has been your experience with it.



These are my requirements

1) Voltage as high as possible: it looks like that will be about 100V
from the ones I saw on Ebay

2) Modest current drain of an amp or two. This should be no problem as
all of them do that

3) Power of about 50W. I can add a fan to keep the heatsink cool if
needed.

4) I do not need a USB current load



Dennis Tillman W7PF



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