Krupi Posted October 30, 2021 Posted October 30, 2021 (edited) Hi Chaps, I could do with some help regarding the wiring of an old Air Ministry Dimmer Switch. I was hoping that it might register like a potentiometer, however as expected it isn't being acknowledged by my Leo Bodnar Board. Any advice would be welcome. Pictures to follow... sorry for the image quality.... I could strip out the internals and hook up a potentiometer but that would be sacrilege. Edited October 30, 2021 by Krupi Windows 10 Pro | ASUS RANGER VIII | i5 6600K @ 4.6GHz| MSI RTX 2060 SUPER | 32GB RAM | Corsair H100i | Corsair Carbide 540 | HP Reverb G2 | MFG crosswind Pedals | Custom Spitfire Cockpit Project IX Cockpit
agrasyuk Posted October 31, 2021 Posted October 31, 2021 Did you get the connections right? If that device is a working linear taper pot with at least 1K of resistance then it should work just fine. Anton. My pit build thread . Simple and cheap UFC project
Krupi Posted October 31, 2021 Author Posted October 31, 2021 I was inspecting it earlier and I can't see how the wiper connects to the contact (white wire). You can see the Solder and wires from the coil on the other contacts. Unfortunately my multimeter died on me the other day so I haven't had the chance to do a proper check. Windows 10 Pro | ASUS RANGER VIII | i5 6600K @ 4.6GHz| MSI RTX 2060 SUPER | 32GB RAM | Corsair H100i | Corsair Carbide 540 | HP Reverb G2 | MFG crosswind Pedals | Custom Spitfire Cockpit Project IX Cockpit
No1sonuk Posted October 31, 2021 Posted October 31, 2021 (edited) Have you got a type number? It looks a lot like it's just an on/off switch to me. OH, and if I'm right, STOP USING IT!!! It looks like the metal bar connects the centre wire to the other two, so you might be shorting your Bodnar card power supply! Edited October 31, 2021 by No1sonuk
crash test pilot Posted October 31, 2021 Posted October 31, 2021 Hi! I found this online https://www.blunham.com/Radar/SignalsMuseum/PDFs/AP1095.pdf and pages 286 and following state it is a potentiometer, but your picture does not show the wire coil - maybe it is missing? Anyway, hope this may be helpful... Cheers! 1 1
No1sonuk Posted October 31, 2021 Posted October 31, 2021 3 minutes ago, crash test pilot said: Hi! I found this online https://www.blunham.com/Radar/SignalsMuseum/PDFs/AP1095.pdf and pages 286 and following state it is a potentiometer, but your picture does not show the wire coil - maybe it is missing? Anyway, hope this may be helpful... Cheers! Nice find. Definitely looks like the actual rheostat is missing. Even if it was intact, 50 ohms is way too low for a Bodnar card. @Krupi: You could do what I did with the starter buttons - use the original as a pattern to design and 3D print a version you can use. See attached picture of my button which uses modern pushbutton switches.
No1sonuk Posted October 31, 2021 Posted October 31, 2021 27 minutes ago, crash test pilot said: Hi! I found this online https://www.blunham.com/Radar/SignalsMuseum/PDFs/AP1095.pdf I've had a chance to look at that more. It's absolutely EPIC! I wish I'd seen the cutaway drawings before I'd made my buttons - I could have got them more accurate. And P25 - Undercarriage position indicator - the one on the Mosquito...
Krupi Posted October 31, 2021 Author Posted October 31, 2021 1 hour ago, crash test pilot said: Hi! I found this online https://www.blunham.com/Radar/SignalsMuseum/PDFs/AP1095.pdf and pages 286 and following state it is a potentiometer, but your picture does not show the wire coil - maybe it is missing? Anyway, hope this may be helpful... Cheers! That is absolutely fantastic, thank you so much! The Rheostat is present, just my terrible phone camera... Windows 10 Pro | ASUS RANGER VIII | i5 6600K @ 4.6GHz| MSI RTX 2060 SUPER | 32GB RAM | Corsair H100i | Corsair Carbide 540 | HP Reverb G2 | MFG crosswind Pedals | Custom Spitfire Cockpit Project IX Cockpit
Krupi Posted October 31, 2021 Author Posted October 31, 2021 (edited) 1 hour ago, No1sonuk said: Nice find. Definitely looks like the actual rheostat is missing. Even if it was intact, 50 ohms is way too low for a Bodnar card. @Krupi: You could do what I did with the starter buttons - use the original as a pattern to design and 3D print a version you can use. See attached picture of my button which uses modern pushbutton switches. This is a slightly better picture... I can actually remove the rheostats winding. So if I 3D print the base and hook up a Potentiometer to the Wiper I will get the feeling of actually turning the dimmer and won't have to destroy anything in the process! Edited October 31, 2021 by Krupi Windows 10 Pro | ASUS RANGER VIII | i5 6600K @ 4.6GHz| MSI RTX 2060 SUPER | 32GB RAM | Corsair H100i | Corsair Carbide 540 | HP Reverb G2 | MFG crosswind Pedals | Custom Spitfire Cockpit Project IX Cockpit
No1sonuk Posted November 1, 2021 Posted November 1, 2021 52 minutes ago, Krupi said: This is a slightly better picture... I can actually remove the rheostats winding. So if I 3D print the base and hook up a Potentiometer to the Wiper I will get the feeling of actually turning the dimmer and won't have to destroy anything in the process! Ah. I see it now. Yeah, a new base would be the way to go. A standard pot will give a wider throw than the real one (270 degrees, rather than what looks like 180), but I don't think that's really a problem.
Krupi Posted November 4, 2021 Author Posted November 4, 2021 (edited) Success! Designed the body. Fortunate to have a friend with a 3D printer, rheostat winding fit perfectly! Fit perfectly and it works, as it was only a prototype it was only a rough print and some parts have snapped now so a few small tweaks to improve the design. Very happy as all I had was my old mans micrometre Not even digital Edited November 4, 2021 by Krupi Windows 10 Pro | ASUS RANGER VIII | i5 6600K @ 4.6GHz| MSI RTX 2060 SUPER | 32GB RAM | Corsair H100i | Corsair Carbide 540 | HP Reverb G2 | MFG crosswind Pedals | Custom Spitfire Cockpit Project IX Cockpit
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