Source for 40pin DIP Heatsink?

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msansom
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Source for 40pin DIP Heatsink?

Post by msansom »

Anyone know a source for 40 pin DIP heatsinks? Not the clip on type, the extruded type.

Thanks,
I'd like to say thank you on behalf of the group and ourselves and I hope we've passed the audition.
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siggi
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Re: Source for 40pin DIP Heatsink?

Post by siggi »

My ZX81 web-server: online since 2007, running since dec. 2020 using ZeddyNet hardware
http://zx81.ddns.net/ZxTeaM
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msansom
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Re: Source for 40pin DIP Heatsink?

Post by msansom »

Ausgezeichnet!

Thanks. That's exactly what I'm looking for.
I'd like to say thank you on behalf of the group and ourselves and I hope we've passed the audition.
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1024MAK
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Re: Source for 40pin DIP Heatsink?

Post by 1024MAK »

Don't forget to buy some for Moggy. He loves them, so send him some at least :lol:

He especially likes them fitted on hot ULA chips inside a nice warm Zeddy with hardly any airflow so that the ULA can continue to cook nicely :P

Mark




















<Me dives for cover under a pile of Quantum Leaps>
PS did I go too far? It's still early morning for someone who was on nights last week...
PPS for those who don't know, this subject of fitting a heatsink to ULA chips has come up rather a lot of times before, best you try a search...
Also have you/are you going to replace the 7805 with a switching type, and/or use a 7.5V to 9V regulated external PSU?
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Moggy
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Re: Source for 40pin DIP Heatsink?

Post by Moggy »

Nice one Mark I fully deserved that one. :lol:

Oddly enough I have just ordered a couple of switching regs from Farnell but have had to do it on-line since they closed their bloody trade counter GRRR! (my new rant topic)
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msansom
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Re: Source for 40pin DIP Heatsink?

Post by msansom »

1024MAK wrote:Don't forget to buy some for Moggy. He loves them, so send him some at least :lol:

He especially likes them fitted on hot ULA chips inside a nice warm Zeddy with hardly any airflow so that the ULA can continue to cook nicely :P

Mark


<Me dives for cover under a pile of Quantum Leaps>
PS did I go too far? It's still early morning for someone who was on nights last week...
PPS for those who don't know, this subject of fitting a heatsink to ULA chips has come up rather a lot of times before, best you try a search...
Also have you/are you going to replace the 7805 with a switching type, and/or use a 7.5V to 9V regulated external PSU?
You guys haven't fitted your ZX81/TS100s with fans?


Actually, here's an idea for a no impact mod ..... put your ZX81 on top of this and power it with a USB wall wart:

https://www.amazon.com/Cooler-Master-No ... laptop+fan

There are enough holes in the bottom and sides so that that would make a difference. I have one of these under my ASUS wifi router which runs uncomfortably hot to me. Been running 24/7 for over a year. If I were to set my TS1000 on it I'd probably rig in a series resistor to bring the fan speed down a little. This will make a significant difference. There are similar units to be found at even lower prices.

That aside, you will make a slight difference in die temp without good circulation, but it is clearly far from optimal.

I have procured a 9V regulated offline switcher to replace the original PSU. Makes a significant difference on the 7805, and helps the ULA by lowering the interior ambient, but obviously doesn't reduce the ULA dissipation itself.
I'd like to say thank you on behalf of the group and ourselves and I hope we've passed the audition.
Moggy
Posts: 3231
Joined: Wed Jun 18, 2008 2:00 pm

Re: Source for 40pin DIP Heatsink?

Post by Moggy »

Hang on whilst I just clear my throat COUGH COUGH switching reg switching reg COUGH COUGH.

Who left this here?....
http://uk.farnell.com/tracopower/tsr-1- ... dp/1696320

Not sure where you are in the world but you get the idea,9v regulated wall warts also good and am loving that thin profile fan. :D

With Marks blessing,I hope, I include one of his excellent posts explaining why the damn thing runs so hot.
The thread can be found here.
viewtopic.php?f=7&t=2201&p=22570&hilit=heat+sink#p22570

QUOTE.

"Postby 1024MAK » Sat Jan 21, 2017 8:27 pm
Using ZX81 2C184E and 2C210E ULAs as an example, These are most likely Ferranti ULA 2000 series very high speed CML (Current-Mode Logic cell) types, that have the following specs: max. clock speed 20MHz, gate delay 8ns, gate current 210µA, matrix size 15 x 15 x 1, total matrix cells 225, total peripheral cells 40.

The CML type has a Vcc to suit the logic it is interfacing to (3.5V to 5.5V). The peripheral cells run directly from this supply. The CML matrix cells use a 0.95V supply and are fed via on chip series voltage regulators. If required, the regulators can have their own supply pin (Vreg), in which case the input supply voltage can be between 1.3V and Vcc to minimise power dissipation without compromising speed. Otherwise (like in the Sinclair ZX81 design) both are fed via the same power pin (the ZX81 ULA only has a single positive power supply pin).

As well as the regulator circuitry, a large power consumer is the peripheral cells.

To construct a logic gate, one or more CML matrix cells are needed:
Buffer =1 cell
2 input NAND gate = 1 cell
3 input NOR gate = 1 cell
monostable = 2 cells
data latch = 3 cells
binary divider with preset and clear = 3 cells
D-type flip-flop with preset and clear = 6 cells"

It seems it doesn't help having all the ULA's connected up instead of the 3/4 internal connection recommended by Farranti.

As a final curiosity in the last thirty odd years my only ULA failures (as far as I can ascertain) have been from clumsy power on/off whilst attaching peripherals and never sudden failure through heat damage so the ULA is probably more hardy than we give it credit for and its scarcity is what gives us cause for concern not its fragility and if truth be told none of the chips inside the 81 run hot enough to warrant heat-sinking (damn I promised I wouldn't start ranting about heat-sinks again).
rom475
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Re: Source for 40pin DIP Heatsink?

Post by rom475 »

Rather than trying to find a heatsink I cut one from a medium profile,(1/2" tall), unit that came off a video card...I cut it into a reverse "H" with the center being 20mm square,this square would enable me to apply a 20mm 5vdc brushless fan for even more cooling...It being 1/2" tall and 20mm square made it so that there was no interference with the Z80 chip and the Astec UM1082 RF Modulator...
Last edited by rom475 on Mon Feb 05, 2018 9:32 pm, edited 1 time in total.
paul ron
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Re: Source for 40pin DIP Heatsink?

Post by paul ron »

don't forget to buy some of that heat transfer cream.
The more you say the less people hear.
rom475
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Re: Source for 40pin DIP Heatsink?

Post by rom475 »

Heatsink silicone is an obvious need whenever heatsinks are used for thermal transfer...
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