DHT Heater using VCCS - PCB or Kit (Possible Group buy)

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Ali Tait
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#1051 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Ali Tait »

The thought was to build the boards up and tap holes on the top of the heat sinks, drill corresponding holes in the chassis, so top of heat sink would bolt to the chassis.
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#1052 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Max N »

RhythMick wrote: Tue Feb 12, 2019 3:02 pm
Max N wrote: Sun Feb 03, 2019 12:53 pm
Andrew wrote: Sun Feb 03, 2019 12:22 pm The "small" ones will do 300B and everything downwards, the big ones are really for 2A3, nothing I have will do a GM70 without serious hacking.

Andrew
I'd like 4 pcbs please Andrew. Also happy to buy any components for the boards if you have surplus stock you want to get rid of.
Max I have 6 spare (small) boards from Andrew which I plan to use shortly. I'm going to be putting in an order (either Farnell or RS) soon so let me know if you need components. We're unlikely to cross any significant price points but you never know - plus I have spares of some items.

Same applies if anyone else needs components for the boards.

EDIT - there are some savings to be had. For example the Panasonic caps are £1.78 <10, £1.05 between 10 and 24
Thanks Mick but I’m sorted now.
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#1053 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by RhythMick »

Ali Tait wrote: Tue Feb 12, 2019 11:41 pm The thought was to build the boards up and tap holes on the top of the heat sinks, drill corresponding holes in the chassis, so top of heat sink would bolt to the chassis.
Yeah I'm struggling to picture that. What heatsinks are you planning to use, the Fischer ones which Andrew supplies? If so there's no flat horizontal surface to mount to the chassis. What am I missing?
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Ali Tait
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#1054 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Ali Tait »

I was round at Mark’s last week and saw some completed boards. They had flat tops so I presumed mine would too.
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#1055 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by RhythMick »

Ali Tait wrote: Wed Feb 13, 2019 9:09 am I was round at Mark’s last week and saw some completed boards. They had flat tops so I presumed mine would too.
This is the small board using the Fischer heatsink. So I think I see what you are getting at, you're going to put threaded holes in the top of those heatsinks?
1550057512534157.jpg
Last edited by RhythMick on Wed Feb 13, 2019 11:34 am, edited 1 time in total.
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#1056 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by IslandPink »

There's enough land on the top of the 60mm (ish) heatsinks Andrew supplies to keep the smaller board stable, you tap an M3 hole down each side between the fins.
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#1057 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by RhythMick »

IslandPink wrote: Wed Feb 13, 2019 11:34 am There's enough land on the top of the 60mm (ish) heatsinks Andrew supplies to keep the smaller board stable, you tap an M3 hole down each side between the fins.
Got it thanks. I thought there was a ridge on the top which would prevent that but I'm wrong.
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#1058 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Andrew »

A 300B driven by the small board should be fine inside a chassis, Ali, at least based upon my experience with Colin's 300B amps.

I have not heard of any boards being frazzled yet, I would expect some would have reached a few thousand hours running by now.

The only dead the ones so far, were the ones Mark (sorry Mark) blew up when he accidentally attached a reversed polarity external supply instead of on-board the pre-reg.

If anyone wants to post up feedback on the state of the boards/modules after prolonged use, that would be both useful and educational.
Analogue, the lost world that lies between 0 and 1.
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#1059 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by IslandPink »

It wasn't a complete frazzle, Andrew - just the little 8-legged things which go off like a fire-cracker !
I've had the small ones working on the 4P1L's happily since we did the prototype work, but those don't dissipate much heat.
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#1060 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by RhythMick »

8 of them have been working nicely in Geoffs amp for about 6 months, no issues.

12 of them in mine for about 6 weeks.
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#1061 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Ali Tait »

Ok thanks chaps, looks like Ive nothing to worry about there. I was just concerned about running four inside a chassis. I’ll go with the usual 9v secondary for the tranny then.
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#1062 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by izzy wizzy »

Is there a supply of these boards available? Or some other arrangement? I'm after 4 to supply 4P1L. Thanks.

Cheers,
Stephen
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#1063 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Ray P »

I'm also planning to use a couple of these in a 4P1L driver stage for my MoFo project.
Sorry, I couldn't resist!
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#1064 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Andrew »

izzy wizzy wrote: Wed May 01, 2019 8:09 pm Is there a supply of these boards available? Or some other arrangement? I'm after 4 to supply 4P1L. Thanks.

Cheers,
Stephen
Steven,

I am out of the 2A3 boards, but have plenty the ones with the heatsink on-the-pcb, which is ideal for 4P1L. Drop me a PM.

Andrew
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#1065 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by pre65 »

I seem to remember someone (Nick ?) suggesting there may be a higher power board coming soon that could be used with 833a.

Thats 10v @ 10A or maybe 2 x 10v @ 5A like Rod Coleman does.

As I'm getting enthusiastic about my 833a rebuild I'd like to know what may be available.

I'm happy to test any prototypes if that helps. :)
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