Randy Pierce Posted December 10, 2022 Posted December 10, 2022 HI and thanks! wiring up this little rascal from the diagram, and it looks like the brush holder wires and the stator wires all hook to source, but with the resistor in the circuit for the low speed at switch. Am I looking at this correctly? It runs, but at ridiculous rpm, and wont accept a speed reduction from a fan speed controller i use on all my fans. The sparking at the brushes is quite extreme. I have checked the stator at about 4 ohms and checked the armature per youtube vids and it checks ok except one of the commutator bars checks slightly lower resistance than the others when checked bar to bar. Maybe I am missing something very obvious with the wiring???? Many thanks, Randy Quote
Jim Kovar Posted December 10, 2022 Posted December 10, 2022 (edited) 1 hour ago, randy pierce said: ...the brush holder wires and the stator wires all hook to source... Both "to source"? Which way? Edited December 10, 2022 by Jim Kovar Quote
Randy Pierce Posted December 11, 2022 Author Posted December 11, 2022 Thx Jim, I hooked it up as a shunt, and it must need the series hookup. I will get on that! Quote
Randy Pierce Posted December 13, 2022 Author Posted December 13, 2022 Jim, the series hookup was the right pattern. The little fan runs runs very nicely now. The nichrome wire for the low speed was shot, so will need to come up with a fix for that to make it right. Have tried the diode replacement, but that doesnt make a difference. Going to need more info to to have a second speed on this fan, and do not want to use a big resistor due to the the heat issue, Appreciate the help, Randy Quote
Russ Huber Posted December 13, 2022 Posted December 13, 2022 (edited) One half wave diode inline on the power cord to the motor should slow it down roughly 700 RPM. Those little guys can cook around 3500-3700 RPM on full wall current. You can put the diode in the plug. It will rectify the AC sine wave and slow mighty mouse down at the same time. Edited December 13, 2022 by Russ Huber Quote
Paul Carmody Posted December 13, 2022 Posted December 13, 2022 (edited) I cross referenced the diode # Radio shack not available and expensive a couple on eBay.I have some from Amazon that are 3A 1000v. Here’s the part number and a diagram for reference.I don’t believe the larger amp # is a bad thing. Edited December 13, 2022 by Paul Carmody Quote
Russ Huber Posted December 13, 2022 Posted December 13, 2022 Full & half wave rectifiers. Shop around on the web for equivalent rectifier ratings roughly 3-4 amp/ 600-1000 volt for best bang for your buck. (Pack of 10 Pieces) Chanzon KBL410 Bridge Rectifier Diode 4A 1000V KBL-4 (SIP-4) Single Phase, Full Wave 4 Amp 1000 Volt Electronic Silicon Diodes: Amazon.com: Industrial & Scientific BOJACK 1N5408 Rectifier Diode IN5408 3 A 1000 V DO-201AD Axial 5408 3 amp 1000 Volt Electronic Silicon Diodes(Pack of 50 Pieces): Amazon.com: Industrial & Scientific Quote
Randy Pierce Posted December 13, 2022 Author Posted December 13, 2022 Thanks All, A cross ref of the radio shack diode gave me an NTE equiv and I have several now. [nte156, 3a, 1000v]. I'll try one in the plug end, and having a digital tach I can tell exactly what the diff is. Another thing I am doing on most all fans is putting a 2 amp micro fuse in the power line for safety. Some years ago I had a bad stator that ran the fan for about 3 minutes and then went to short, with a fire. Was a 4th of july gig right there on the bench. Don't want to see that again. Randy Quote
Steven P Dempsey Posted December 14, 2022 Posted December 14, 2022 I ordered 30 and got 300, free for shipping!! I through a few in boxes I ship Quote
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