Sorry ccjersey & Skogsgurra this is a follow on question to an earlier post.
"using motor as generator..." Jan 5th
The DC supply (used an AC>DC converter) was just used to test the load and DMM's. It had nothing to do with testing the rotors.
We are ordering more motors with higher ratings...
Sorry for so many questions Waross.
Not using power source as load. I must have been unlcear in the post.
Load for the generator (motor) is a combo of the bulb and a variable carbon pile set at 10 amps.
Hooked the load onto the 15V DC power source to make sure the meters were in line with...
Thanks Waross
Meters are new. They are RMS DMM's. Light bulb load is relatively small portion of overall load especially on amp side. Bulb is rated at 300ma.
How far off could the DMM volt and amp readings be? Is it +/- 5%, +/- 20%?
Also does it make a difference if all I am comparing is...
In ref to "using motor as generator..." Jan 5th:
We had placed a small 15V .5A incandescent bulb in front of the main resistive load, just for a kind of visual cue.
Noticed when testing circuit with a stable 15V DC power source there was a differnence in bulb luminosity. Took almost 24V to...
Motor's about 2.5 inches. Wind tunnel is only 1.5 meters and we need a fair amount of clearance for the test rotors to avoid any forward overpressure so it limits the size of the rotor and thereby the motor.
Thanks waross
Was thinking something like that, although not that clearly. I ran a test with a stable power source and the load. the amps measured at 10.
Voltage on the known source was 15 and that was the voltage reading. Guess I assumed that the volts would go up with the rpm's but thought the current...
Thanks ScottyUK
"So.... everything looks pretty normal: what is the anomaly you think you are seeing?"
Basically misconception on my part. EE is definately not my speciality and I thought that the output was limited by the voltage and current of the load.
Thanks again
Thanks Waross
"10...
Have been testing rotor designs on a small prototype wind rig in a small wind tunnel using a 24V DC PM motor loaded with a variable resistive load as a generator. Results we have been getting seem out of whack with load characteristics.
Load is set at 12V 10A which given our small rotor size...