Another CCS for tubes/valves: PCBs

[Doc B.]

Since you guys seem to be having some trouble pulling this together I will mention once more that we have been using this CCS design for many years, and we have boards.

We have a couple of flavors. The older design is one we have for sale on the website as a kit with transistors and LEDs and fairly extensive documentation. It only needs the addition of the resistor values needed for setting the specific bias and plate current for a given application. The kit contains two cascode constant current sources, one per board. The board is perfectly functional and easy to populate, but I won't say that it's the most compact or logical layout. Since you guys are very DIY I could probably be talked into selling boards only for a reasonable price if you can pull together a group buy and plan to do your own parts acquisition and tech support within the community. Here's a pic of a couple of them.



A newer design has space for two of the same design CCSs as the original board, plus the SS components of a pair of hybrid tube/SS shunt regulators. This is what we currently use in most of our products. It has a more dense layout and this one doesn't have stand alone documentation at this time, but it does have a component screen. If you guys are adventurous enough to tackle this board without a lot of tech support I could probably make it available in quantity for a group buy as well. Here's an image of three of the boards in a couple of different configurations. These boards can also be split in half to make individual CCS/shunt regs.



If this is of interest, feel free to volunteer someone from your community to be the facilitator and have them contact me, and I'll be happy see what I can do to make a good deal for the group.

[beetel]

Tube Prototype PCB with CCS Pads 9-pin Mini


http://cgi.ebay.ca/Tube-Prototype-PC...QQcmdZViewItem

[Bas Horneman]

Mmm, Doc. B.'s shunt reg boards look interesting. For CCS I always use DN2540's..very easy.

But I've read that the shunt regs improved the Bottlehead kits even more. On can use half of a driver tube as driver and the other half I believe is used in the shunt reg.

[dsavitsk]

Okay. I could be convinced to do this project. But, my experience with PCB manufacture is that the multiple boards on one sheet with v-scoring will drive up the price considerably. Moreover, I think lots of people would only want one board or another.

So, if I were to do it, I'd offer 3 different boards and run it like other group buys where people need to agree to, and pay for, boards in advance. I would think $2 to $3 per board plus some shipping would be reasonable. There would also be no reason not to include boards for single and dual IXYS chips, I suppose.

The only rub is that as a group buy it would need to be at the buyer's risk -- that is, I would not take back boards that had a manufacturing error, or that had a design error (presumably lots of eyes would look at them before they were ordered) and boards lost in shipping would not be my responsibility (really, the only boards that ever seem to get lost in shipping are those going to Italy.)

So, if people are interested, let me know and I'll post up the designs and start a group buy thread ...

[Ryssen]

So, if people are interested, let me know and I'll post up the designs and start a group buy thread ...

I am..

That was what I worried about when managing a GB,that boards would get lost on the way,fortunate it all went well..

[valveitude]

So, if people are interested, let me know and I'll post up the designs and start a group buy thread ...

I'm interested.

[leadbelly]

This thread looks like it is about to get out of control. I recommend that anybody discussing Doc B. or dsavitsk boards start a new thread, and that the original boards that are now being handled by myself, planet10 and beamnet remain in this thread. Don't take this is as mean spirited, as I would be very interested in participating in GB's for those boards as well

[dsavitsk]

I think that's a good idea (the new thread, that is). Also, I'd rather not have to run a group buy, it just seems like there are lots of folks looking for boards and that it is not going anywhere.

As for the Bottlehead designs, with all due respect, based on past dealings with them, I have my doubts about getting these down into the $2 to $3 range. I also have my doubts about the designs being made public and being discussed. If Doc B wants to post some schematics, enter into a discussion, and give a little back to the community, then I am all in favor of going that route.

Also, what might end up being easier for everyone, is to put a few designs up complete with Gerbers. Then, you could pick your favorite CCS boards and send them to Olimex who will panelize them onto a single sided PCB that will hold 10 to 12 small boards for EUR 24 + shipping. Presumably, few people need a dozen, so a small side market or 2 to 3 person group buys could be arranged. The transaction costs per board are a little higher, but it is a lot easier for me to not have to manage hundreds of boards, and people might be more likely to get what they want.

http://img.photobucket.com/albums/v3...lett/sleep.jpg

[dsavitsk]

So, it looks like 24mm X 40mm is pretty easy to do, which would mean 16 boards from Olimex for ~30 shipped.

[leadbelly]

Originally posted by dsavitsk
So, it looks like 24mm X 40mm is pretty easy to do, which would mean 16 boards from Olimex for ~30 shipped.

I suggest that you orient the pads for the power transistor so that it can be heatsinked. You can discuss this in the new thread

Is it just me or has this thread now gone backwards?