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 » Sun Aug 25, 2019 3:21 pm

izzy wizzy wrote:
Sat Aug 24, 2019 5:15 pm
Check the value of the 47k resistor feeding the 100u capacitor. If it was low or has been shorted via a solder blob, the cap will charge up stright away rather than following slowly.
Ok thanks will do

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

Post by Andrew » Mon Aug 26, 2019 10:35 pm

Also check the 470k resistors and the 470nF caps.
Analogue, the lost world that lies between 0 and 1.

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

Post by RhythMick » Mon Aug 26, 2019 10:37 pm

Thanks. Work has dragged me away from hifi I'm afraid. I'll check later this week.

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

Post by izzy wizzy » Sun Oct 27, 2019 5:47 pm

It's been a while since I heatsinked anything.

For higher currents, I have a finned heatsink. I have silicon isolation tabs which I believe don't need thermal compound stuff like the old mica ones did from memory. I don't have heatsink compound.

Can I get away without the compound at all; devices straigh to sink? Would it be better to use the silicon tabs even though I don't need them isolated?

Cheers,
Stephen

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

Post by RhythMick » Sun Oct 27, 2019 5:53 pm

I think you're right that the silicon type don't need compound, but the datasheet will tell you.

If you need it I have 2 spare syringes of compound, happy to send you some, no idea why I bought three.

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

Post by izzy wizzy » Sun Oct 27, 2019 6:21 pm

Your reply prompted me to know what to look for. I thought I had the compound in a tub and couldn't find it but you saying syringe made me go look in the shed and bingo, found syringe of the stuff. Sorted thank you.

Cheers,
Stephen

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

Post by RhythMick » Sun Oct 27, 2019 6:56 pm

Lol glad I could help

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

Post by IslandPink » Sun Oct 27, 2019 7:24 pm

Phew !
I was fearing your room would be full of the smell of magic smoke, for a while there.
"The bass is the king of the instruments - it has no known natural predator" (Wobble)

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