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

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

Post by RhythMick » Thu Apr 05, 2018 12:15 pm

andrew Ivimey wrote:
Thu Apr 05, 2018 11:44 am
I've done this tho not with Andrew's. The modules were variable and I was using 7.5 volts at an amp. The transistors / i.c.s were about six inches away from the modules. No probs.
Thanks. So unless Andrew advises otherwise I'll consider this an option.

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

Post by Andrew » Fri Apr 06, 2018 4:45 pm


So, is it OK to mount the transistors on heatsinks remotely and run wires to the boards?
Not sure it would be my first choice; it will certainly increase strays/parasitics and there was a lot of work in the layout of the PCB to keep noise to a minimum.

And, don' forget both transistors are carrying the full current, so reasonably sized wires would be required. As I said, they work better very close to the DHT and using as short a wires as practical.

Having said that, you can do what you want with them, but to be fair to everyone involved, they become your problem if they don't work.
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RhythMick
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Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by RhythMick » Sat Apr 07, 2018 12:11 pm

Thanks Andrew.

One more question please. Are the heatsinks at ground potential or are they live?

Badly phrased. I mean are the backs of the transistors live, needing mica spacers?

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

Post by Andrew » Sun Apr 08, 2018 6:44 am

I mean are the backs of the transistors live, needing mica spacers?
A isolating spacer is needed unless you replace the D44H11, providing you don't need to be in the upper end of the current specs, the regulator is an all plastic part.

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

Post by Andrew » Sun Apr 15, 2018 6:22 pm

OK, now that Easter is behind us I am in a position to start building up the group buy and, all being well, parts availability not withstanding, ship in a week or two.

There has been a few changes to the orders and so I have lost track of where we were. For the sake of clarity and to avoid disappointment, could everyone add the their order to this thread so that we build up a list of who want's what.

What I am after is you copy the previous post that includes the order list as it stands and add in what you need at the end.

This is self editing and avoids me making a mistake.

So person #1 adds their order.

Person #2 copies person #1's text and posts a new reply appending their order to the end preserving #1's text.

Person #3 copies person #1's and #2's text and posts a new reply appending their order to the end...

and so on.

thanks,

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

Post by RhythMick » Sun Apr 15, 2018 8:42 pm

Mick : 12 x large

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

Post by thomas » Sun Apr 15, 2018 11:12 pm

RhythMick wrote:
Sun Apr 15, 2018 8:42 pm
Mick : 12 x large
4 x large ones please for me Thomas

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

Post by davebms » Mon Apr 16, 2018 9:46 am

thomas wrote:
Sun Apr 15, 2018 11:12 pm
RhythMick wrote:
Sun Apr 15, 2018 8:42 pm
Mick : 12 x large
4 x large ones please for me Thomas
2 large davedms

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

Post by Nick » Mon Apr 16, 2018 10:48 am

I think he wants each reply to add to a list he can read, so

Mick : 12 x large
Thomas: 4 x large
davedms: 2 x large
Resistance isn't futile it's V / I.

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

Post by Michael L » Mon Apr 16, 2018 11:32 am

Mick : 12 x large
Thomas: 4 x large
davedms: 2 x large
Michael L 2 x small

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

Post by Andrew » Mon Apr 16, 2018 11:39 am

Yes please, thanks for clarifying that, Nick.

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

Post by Michael L » Mon Apr 16, 2018 3:39 pm

Mick : 12 x large
Thomas: 4 x large
davedms: 2 x large
Michael L 2 x large

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

Post by Andrew » Thu Apr 19, 2018 1:16 pm

Neal, did you still want some?

thanks,

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

Post by Neal » Tue Apr 24, 2018 4:44 pm

4 large please
Only the Sith deal in absolutes.

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

Post by RhythMick » Tue Apr 24, 2018 5:58 pm

As per pm, amending mine (and adding Neal)

Mick : 16 x large
Thomas: 4 x large
davedms: 2 x large
Michael L 2 x large
Neal : 4 x large

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