PWM to Analog converter circuit
- Thread starter Tealc
- Start date
ready made channel aluminium is much easier to get hold of and could form most of an enclosure particuarly if the hot component was moved to the other side of the pcb and was bolted rather thans soldered
Would one of these convernt my an older zalman cpu cooler fan to PWM operation they are currently on fanmates at fixed speeds.
Would one of these convernt my an older zalman cpu cooler fan to PWM operation they are currently on fanmates at fixed speeds.
I hear what you are saying with the aluminium channel. There are a couple of considerations, one is the thickness of the bolt on the other side of the transistor and the fact that I don't actually have any suitable bolts. I could probably make room for the bolt head if I changed the layout of the circuit a touch and moved a resistor out of the way.
Yes it would. That's what it is designed for, well not specifically yours but you know what I mean.
It's 18mm wide.
I could use thermal adhesive but I'd need to buy some, and the channel too. The contact area on the transistor is really quite small and I'm unsure whether it would be strong enough to hold it in place.
Thinking about it I could mount the resistors underneath the board, or invest in some SMD resistors and that would give me space for a bolt. They are nearly the same price as through hole ones.
Just trying to use what I have to hand rather than having to buy stuff all the time as it's really surprising how quickly the parts cost mount up.
I could use thermal adhesive but I'd need to buy some, and the channel too. The contact area on the transistor is really quite small and I'm unsure whether it would be strong enough to hold it in place.
Thinking about it I could mount the resistors underneath the board, or invest in some SMD resistors and that would give me space for a bolt. They are nearly the same price as through hole ones.
Just trying to use what I have to hand rather than having to buy stuff all the time as it's really surprising how quickly the parts cost mount up.
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Could end up with airflow through the inside to help cool. Could do similar on top like it is now but use angle instead of channel on one side from socket to end of board. I could knock out a couple of each with some scrap copper I have here... as long as you don't beat them flat like the last batch 
I wonder if it's really necessary though. I mean it gets warm but provided it's kept to 3-4 fans it doesn't get hot enough to cause an issue.
Ideally you'd have a moulded bit of aluminium or copper with passive cooling thickness vanes which would have a nice hole drilled in it. A small bolt would connect them together with a dash of MX3 or something.
There are of course heatinks already designed for transistor that have this sort of shape going on.
http://www.ebay.co.uk/itm/10-x-TO22...al_Components_Supplies_ET&hash=item415ea4a03f
£1.15 for 10.
That's not too bad actually. Might order some if these two sell.
I had one of these running over an Ampere with one of Resident's heatsinks and it didn't get as hot as ther copper slab. It's the surface area that makes the difference. Plus the grooves help the heat move away, whereas a flat surface doesn't.
Ideally you'd have a moulded bit of aluminium or copper with passive cooling thickness vanes which would have a nice hole drilled in it. A small bolt would connect them together with a dash of MX3 or something.
There are of course heatinks already designed for transistor that have this sort of shape going on.
http://www.ebay.co.uk/itm/10-x-TO22...al_Components_Supplies_ET&hash=item415ea4a03f
£1.15 for 10.
That's not too bad actually. Might order some if these two sell.
I had one of these running over an Ampere with one of Resident's heatsinks and it didn't get as hot as ther copper slab. It's the surface area that makes the difference. Plus the grooves help the heat move away, whereas a flat surface doesn't.
Hello
I am French and I use google translation.
I have a PH-TC14PE with 3 fans PH-F140TS.
I made a request to have an adapter for Phanteks PWM, I received quickly.
The adapter is calibrated for two fans.
After research I find this discution that interested me.
Having some knowledge of elementary electronics, I start looking more closely this adapter.
The diagram looks like it has enormously
http://www.w9xt.com/page_microdesign_pt12_hv_pnp_switching.html
So I decide to replace R4 in order to increase the output current of the B772.
I find a value (R4 = 550ohms (580 / / 10 000), which provides the full range of regulation:
20% = 600 rpm
100% = 1200 rpm
I set up a small radiator on the B772 I insulate with shrink tubing-retractable (note the radiator is connected to +12 V)
I preferé power adapter with a molex the intermediary, rather than the motherboard (11.7v vs 12.1V)
For information before modif
[email protected] supplied at 1.32V in a housing ATCS 840 (max 125W under Linx test at 60 ° C; room at 25 ° C 3 * 1200rpm
Now 65 ° C for 3 * 900rpm.
it is now almost inaudible
I'm glad my little adaptation.
I am French and I use google translation.
I have a PH-TC14PE with 3 fans PH-F140TS.
I made a request to have an adapter for Phanteks PWM, I received quickly.
The adapter is calibrated for two fans.
After research I find this discution that interested me.
Having some knowledge of elementary electronics, I start looking more closely this adapter.
The diagram looks like it has enormously
http://www.w9xt.com/page_microdesign_pt12_hv_pnp_switching.html
So I decide to replace R4 in order to increase the output current of the B772.
I find a value (R4 = 550ohms (580 / / 10 000), which provides the full range of regulation:
20% = 600 rpm
100% = 1200 rpm
I set up a small radiator on the B772 I insulate with shrink tubing-retractable (note the radiator is connected to +12 V)
I preferé power adapter with a molex the intermediary, rather than the motherboard (11.7v vs 12.1V)
For information before modif
[email protected] supplied at 1.32V in a housing ATCS 840 (max 125W under Linx test at 60 ° C; room at 25 ° C 3 * 1200rpm
Now 65 ° C for 3 * 900rpm.
it is now almost inaudible
I'm glad my little adaptation.
Yes that's basically the same circuit but I didn't use R4 to make a voltage divider and instead control the current flowing through B772 at a later point. I find that even a small change in R4 has a profound difference on current running through B772 so wasn't really suitable for a totally adjustable circuit.
You could have changed the 1k resistor on the Phanteks board to something like a 620 Ohm 1/2W resistor and that would have had the same effect.
You could have changed the 1k resistor on the Phanteks board to something like a 620 Ohm 1/2W resistor and that would have had the same effect.
Sorry, we are not looking all did the same thing.
My goal is to adjust the adapter to work with pwm 3 Phanteks fans, since by default it is calibrated for 2.
I killed the S8050, I replace it with a BC337-16, R4 = 500ohms now
But it is true that modify its behavior so that it fits almost all situations is a very good idea.
I do not understand about the resistance of 620 ohms.
I have a strong difference between 1000 and 500 ohms. (1/4w only)
My goal is to adjust the adapter to work with pwm 3 Phanteks fans, since by default it is calibrated for 2.
I killed the S8050, I replace it with a BC337-16, R4 = 500ohms now
But it is true that modify its behavior so that it fits almost all situations is a very good idea.
I do not understand about the resistance of 620 ohms.
I have a strong difference between 1000 and 500 ohms. (1/4w only)
Ah right. I thought you modified the circuit you linked to onto the Phanteks board by adding an extra resistor to ground before the base of the transistor. Now I see you just swapped out the 1k resistor for something else, which is what I mentioned above.
With your 500 Ohm resistor you are actually exceeding the rating of a 1/4W by the way, not my much (0.288W) but you really need some overhead with these things. Might be better to put two 1k 1/4w resistors in parallel.
With your 500 Ohm resistor you are actually exceeding the rating of a 1/4W by the way, not my much (0.288W) but you really need some overhead with these things. Might be better to put two 1k 1/4w resistors in parallel.
