#1 6.3v indirectly heater valve PCB (possible group buy?)
Posted: Thu Mar 01, 2012 8:08 pm
Nick and I have been chatting about doing a PCB for 6.3v DC heater circuit that could provide up 1 amp of pure DC, so that's 3 valves like a ECC88/83/12AY7/5751 and a whole host of 330mA values etc or one 6N6P/5687 etc from the one single PCB.
The circuit uses pretty much standard components, to keep the cost down, but has excellent ripple rejection, probably in the excess of 80db, the Spice sim say no AC component what so ever!
It is set for 6.3v without need for adjustment and is also designed to isolate the valve's heater from the nasties on the output of the 3 legged reg equally, it also isolates the reg from any feedback from the heaters; for high gm valves I found this very effective.
At the moment, we have no idea of cost but the process would be similar to the start up boards, if you remember how we did those?
The PCB would require an external 9v feed from, say, a toroid. The TX will probably be the most expensive part, roughly £8 or £9 from Rapid, I would guess, but don't hold me to that. The remaining parts, excluding PCB will probably be less than that, but I don't know for sure yet.
If the design has enough interest I will build first a prototype on strip board and post the measurements here, so we all know what we're getting, then we will do the artwork for a run of PCBs.
The idea is you buy the parts on the BOM yourselves and Nick, or myself, supply the PCB and any parts that cannot be sourced direct in a single buy from Rapid; this is designed to be easy.
Please register any interest or post comments on the design below; there's always room for improvement.
Andrew
The circuit uses pretty much standard components, to keep the cost down, but has excellent ripple rejection, probably in the excess of 80db, the Spice sim say no AC component what so ever!
It is set for 6.3v without need for adjustment and is also designed to isolate the valve's heater from the nasties on the output of the 3 legged reg equally, it also isolates the reg from any feedback from the heaters; for high gm valves I found this very effective.
At the moment, we have no idea of cost but the process would be similar to the start up boards, if you remember how we did those?
The PCB would require an external 9v feed from, say, a toroid. The TX will probably be the most expensive part, roughly £8 or £9 from Rapid, I would guess, but don't hold me to that. The remaining parts, excluding PCB will probably be less than that, but I don't know for sure yet.
If the design has enough interest I will build first a prototype on strip board and post the measurements here, so we all know what we're getting, then we will do the artwork for a run of PCBs.
The idea is you buy the parts on the BOM yourselves and Nick, or myself, supply the PCB and any parts that cannot be sourced direct in a single buy from Rapid; this is designed to be easy.
Please register any interest or post comments on the design below; there's always room for improvement.
Andrew