Kerry Design mini GRHV\GRLV and JoaMat mini T2 Group Buy

[Blaino]

Can I be added to the group buy for 

8 * GRHVxxx
4 * GRLV78xx
4 * GRLV79xx
4 * main board
2 * Mini T2 board

[judo]

If it was not too late:

2x GRHVxxx
1x GRLV79xx
1x GRLV78xx
1x Main Board

1x miniT2

[mwl168]

Table updated.

[s_r]

Please add me for the following:

4x GRHVxxx
2x GRLV79xx
2x GRLV78xx
2x Main Board
2x miniT2

Thanks.

[mwl168]

Table updated!

Also, some progress updates: I tested the timer, relay and LV sections on the Main Board and they all work as designed. I am very close to sending final boards to fab house for quotes. With some luck with remaining tests, it may happen this week. 

With that in mind, a few things we need to all think about and decide. Please share your thoughts on this thread:

1. A reminder - the GRHVxxx and GRLV boards will not work by themselves as stand alone regulators. The rectifiers, filter caps, current limit circuit for HV are on the Main Board.

2. You can use 78xx/79xx regulators to replace GRLV boards if so desired. In fact, that's how I tested the Main Board.

3. The default timer setup on the main board is about 45 seconds. You can change a couple parts to adjust. The timer and relay circuits are both optional and can also be replaced with external modules.

4. R7, 8, 9, 10 on the GRHVxxx board set the regulated output voltage.

   

A couple of items to think about and decide:

1. We should consider, as I have mentioned before, if to have the GRHVxxx board either fully or partially assembled. I hand-soldered all the SMD parts on the main board. It's manageable. The GRHVxxx is another matter - it's small and operates on very high voltage. Soldering the HN4A51J part alone is no bargain.

2. This GB has dragged on for some time. If you have changed your mind about the item quantities, etc., please post them here and I will update the table. We need final counts to get quotes. 

 

More update to follow!

 

 

 

Edited March 3, 2020 by mwl168

[jose]

Thanks to share your progress MWL.

I keep my units. Personally I would opt for a partial assembly (if the price does not increase too much). Some components are quite complicated to solder.

[judo]

That HN4A51J compared with the TPS7A... regulators seems easy. Maybe I am not right I did not do much similar. Is this the hardest solderable part ? The size is the main problem or stg else?

[mwl168]

Have not worked with TPS7A. 

Hand-soldering a tinny part on a small PCB is a challenge by itself. Add high voltage application which is not forgivable if the soldering job is less than tidy. 

[judo]

Thanks! For the answer and for the much work. You know the the TPS7As were a real challenge with the mini dynalo, Kerry's (and Kevin Gilmore) design. So I thought there were some experiences.

Edited March 2, 2020 by judo

[s_r]

I'll take partial assembly if it means some peace of mind when it comes to the HV boards, personally.

 

[JoaMat]

After looking at posts by Kerry regarding the GRHV boards I think it might be a good idea for builders of the mini T2 to even build Kerry’s regulators. To me those boards seems doable and they aren’t any more difficult than the amplifier boards nor significant higher voltages either. The more you solder the better you get at it.

[G600]

I confirm my interest, assembled boards or not.

Edited March 3, 2020 by G600

[chinsettawong]

Preassembled boards will be nice. 

[Blueman2]

I remain committed to the buy, but definitely prefer as much pre-assembly as possible.  Willing to pay for more assembly, even if there has to be a sub-buy for those wanting it.  

[HatIsMyFriend]

I don't mind either way.

If it's assembled though, would the voltage setting resistors be left blank for flexibility, or would it be set to +400 -460? 

[mwl168]

If we go with assembled GRHVxxx boards, I like to leave the 4 resistors used to set the output voltage blank so builders can configure their desired output voltage, 

These resistors are 1206 parts and fairly easy to solder.

[judo]

Preassembly less fun. I have bought a Quick 861DW hot air station and I would like to play with it.😀

[JoaMat]

Any chance for a GRHVxxx BOM?

[mwl168]

6 hours ago, JoaMat said:

Any chance for a GRHVxxx BOM?

Will post the BOM for the boards on the first post in this thread later when all tests are done. 

[thuytn]

Please add me for 5x mini-T2.

Thank you for your hard work.

[mwl168]

39 minutes ago, thuytn said:

Please add me for 5x mini-T2.

Thank you for your hard work.

Do you just need 5 sets of mini T2 boards or do you also need the PSU boards?

[mumford]

I probably take GRHVxxx fully assembled.  High voltage + tiny smd = high probability of burned pcbs.  I have a hot plate and can do smd soldering.  But I am pretty sure that GRHVxxx is two-sided, and requires hot air or an oven.

[Discom]

Could I adjust to 6x GRHV, 8x GRLV78xx, 8x GRLV79xx, 3x main board, 1x mini T2?

I don't particularly need the GRHVs to be preassembled. If the cost increase is reasonable I wouldn't mind but otherwise I'd prefer to stick with bare boards.

Thanks for your work on this!

[mikeymad]

On 3/2/2020 at 11:05 AM, jose said:

I keep my units. Personally I would opt for a partial assembly (if the price does not increase too much). Some components are quite complicated to solder.

^this

[thuytn]

4 hours ago, mwl168 said:

Do you just need 5 sets of mini T2 boards or do you also need the PSU boards?

I just need the amp boards