Voltage selector / input board for multi-tap power transformers
I designed this board originally for the R120 "Luxuriante" amp, and I'm finally after 3 years getting around to posting the details for it. Here it is in use:
The PCB has switches to let you select the many voltage options on transformers like the Hammond 300 series. It also has inrush limiters and MOVs on it.
It's designed to mount to the same holes that mount the transformer to the chassis. You use a screw through the transformer and chassis, and instead of putting a nut on the back, you put a threaded female standoff there, and screw the PCB to that. Or if you prefer, you can just use longer screws and through hole spacers. There are several different holes to allow mounting to different size transformers.
Here's the schematic:
Here's the bare PCB:
...and dimensions:
The parts list is simple, available from Mouser:
| Qty | Parts | Mfg | Mfg PN | Mouser PN | Notes |
| 2 | TS1, TS3 | Phoenix Contact | 1869237 | 651-1869237 | |
| 1 | TS5 | Phoenix Contact | 1729144 | 651-1729144 | |
| 1 | TH1 | Epcos/TDK | B57237S100M | 871-B57237S100M | |
| 1 | S3 | C&K | L202121MS02QE | 611-L202121MS02QE | Either Q or QE is OK |
| 2 | S1, S2 | C&K | L203011MS02Q | 611-L203011MS02Q | Either Q or QE is OK |
| 2 | Z1, Z2 | Littlefuse | V130LA10CP | 576-V130LA10CP |
The PCBs are available in my eBay store...