Timeline for Building a solid state regulator for a vintage 6 V dynamo
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 25, 2022 at 14:51 | comment | added | clairefromperth | "...connect R3 to dynamo output..." do you mean connect R3 to D+ vs DF? Regulating voltage and current is controlling the dynamo's power output - producing what's needed for ignition and avoiding the production of any energy I'd have a hard time dumping. So I'd need to add to your circuit diagram to accomplish that. | |
| Jul 24, 2022 at 21:10 | comment | added | PStechPaul | The output of the dynamo is proportional to both RPM and field current. So you need to reduce field current as RPM increases. My imperfect simulation regulates the field voltage, but you would want to connect R3 to the dynamo output, which is what you want to regulate. | |
| Jul 24, 2022 at 13:52 | comment | added | clairefromperth | Yep - a power zener would have a big job to do in this application. Is it logical to view my application as needing the regulator to limit the power output of the dynamo to a narrow band - essential feeding a steady current to the field coil across the RPM band? I'm with you on the benefit of a cap | |
| Jul 23, 2022 at 23:46 | comment | added | PStechPaul | The single power zener was used on a motorcycle that also had lights and other loads that used some of the current from the dynamo so it did not need to dissipate as much. Using field current to regulate output voltage is fairly efficient and probably much better than a simple linear regulator. The DC output of the dynamo is probably clean enough for ignition, but a good size capacitor (1000-10,000 uF) may help provide stability. A PWM design would be more efficient, but beyond the scope of this discussion. | |
| Jul 23, 2022 at 14:41 | comment | added | clairefromperth | It seems to me that a zener solution, while simple, translates into having to dump a lot of heat. Since my load is small, isn't it better to only produce the energy needed thereby avoiding having to deal with excess heat? | |
| Jul 23, 2022 at 14:29 | comment | added | clairefromperth | This is a simple and inexpensive solution. In my case, I'm presenting the dynamo with a fixed load (the ignition coil) which, to my naive electrical mind, is pretty insensitive to the cleanliness of the current it's getting. Here's a dumb question: since to me this looks like a current regulation challenge would a Linear Regulator with a cap to stabilize things do the job? | |
| Jul 23, 2022 at 0:56 | history | answered | PStechPaul | CC BY-SA 4.0 |