Electronics > Projects, Designs, and Technical Stuff

Harbor Freight Multimeter Add-on

(1/6) > >>

Wimberleytech:
I use the freebie Cen-Tech multimeter (Harbor Freight gives away from time to time) for testing batteries because it tests them under load.  I have a few of them.  So I designed this 3D-printed add-on so that this meter is a dedicated battery tester.  Still thinking of ways to improve it but works well in the current configuration.

tooki:
That’s cool I guess, but what is the scale used? The manual’s description makes no sense to me:



1.5V at 4mA is 6mW, not 370mW. And I’ve never heard of displaying battery capacity by current, always by voltage under load.

Gyro:
A load current of 25mA for a 9V battery and only 4mA for an AA cell doesn't sound right. That's a moderately heavy load for the 9V but insignificantly low for the AA.  :-\

I assume it's using the same resistor for both. The AA reading is going to give a misleading (high voltage) result.

Stray Electron:
  How/why is it reading 3.5 with only a single 1.5V battery in the adapter?

Gyro:
3.5mA?

It looks weird. It should be measuring the battery voltage while it is under load, not asking the user to try to extrapolate from the current.  :-//

A pretty useless function.

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod