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| How Do I Convert DC Motor To Reverse With SPDT Switch? |
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| andyf:
John, great minds think alike :thumbup: . I drew up exactly the same circuit late last night, after going to the pub and consuming a considerable quantity of beer, so I thought it best to leave it for checking in the morning. I suppose the two new relays RL1B and RL2B, which only handle the small current required by the coils of RL1A and RL2A, could be replaced with transistor switches, with the addition of protective diodes across those coils. Snub, though it's more complex than your drawing and needs another two relays, John's latest version allows you to work the motor through your existing momentary switch. Good luck, and don't set the car on fire! Andy |
| John Swift:
Hi snub, on your diagram just swap terminals 30 and 87 so the motor is connected to the common terminal 30 on each relay otherwise you will short circuit the supply ! before I posted the wiring diagram ,I had to downloaded the PDF data for an automotive relay to add the relay terminal numbers if the switch is not allready connected to fuse , you could connect the switch common terminal to the motor supply fuse in the diagram so all the wiring is protected John |
| snub:
Thanks, John. After studying the schematic I find you are correct about terminals 87 and 30. I will correct my diagram so no one else fries something. On another note, I was just thinking about a feature that most cars with power windows has. And that would be the automatic down on the drivers side. Just a quick touch of the switch and the window goes down and stops automatically. I will have to delve into this and see how it's accomplished. Might be something I could incorporate into my design. In the mean time, I'm searching for a suitable motor. The original ran at about 10 RPM. The new one would have to have dual shafts like the one pictured below. Finding one with the right RPM has been a struggle, but I guess theres no reason why I couldn't use a PWM controller. |
| John Swift:
Hi snub , a speed control like UK1102 from Canakit.com could give you the way of controlling the speed its available as a kit or ready made using two pole relays as in the circuit in the earlier post will keep the motor running until the limit switch is tripped I'll have a look for the info , I know Lucas made them John |
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