Recent content by dmax

Just occurred to me, you could take one of the PWM units, and Hack it, by replacing the Variable Pot. with a Thermistor; But it would need some experimentation. The LE version has the same 3 x 4 Pin Chassis fan connectors.

Whether it is the Resistor OR a Transistor, it still needs to dissipate the heat, that is why Switch Mode supplies are used today; As one runs at, say, 55% efficiency, and the other at 90% A MOSFET circuit will only work, if it's designed to be installed in the 12 volt supply line, as has been...

Further to my above recommendation, I would suggest the following:- http://www.ebay.co.uk/itm/PWM-DC-12V-2A-Adjustable-Motor-Speed-Controller-for-Brushless-Fan-/261978142374? Or:- http://www.ebay.co.uk/itm/DC-Motor-Speed-Regulator-Controller-Switch-6V-12V-24V-3A-PWM-/252035720628? as it runs at...

NO, you cannot rely upon them Starting on 5-7 volts, for the reason that I alluded to in my previous reply. In order for them to start reliably, they must start at 12 volts, then be reduced. The stupid aspect w.r.t. using a power resistor, is that it WILL generate vast amounts of Heat...

The fact that The/A, motor runs on DC, only describes part of its Specification. ALL (as far as I am aware) use Switched Transistor's in the ground lead, which is controlled by a Hall Effect sensor (Switch), and a 3 wire fan works on 12 volt, (or 5 volt in laptops). It IS possible to reduce the...

I still maintain that this circuit will not function correctly, with standard Computer Fans, for the reasons in my previous reply. By Pulsing the Ground Lead, you interfere with the Switching Transistors which energise the Motor Coils; That is why the control HAS to be in the 12 volt supply...

Let's be Very specific; Fan Speed control is not regulated by Voltage, but by PWM, and, by convention, any 3 pin fan connector WILL power the fan at Full voltage, and hence, Full Speed; The only variation, is via. the 4th wire, which regulates the Fan Speed by virtue of the control circuit of...

Just a quick reply; You do not need anything as complicated as the above circuit, as your Pump has only 3 wires, there is NO PWM control signal, so, just use the 3 connector plug, into you Mother-board, where the 3rd wire will indicate the Pump motor Speed. A google search linked me to this...

The reason that I came to this link, is because I was looking for a quick design to run a (5 volt) Blower (think laptop) in an HTPC, and most available fans are of a 3 wire configuration. I have now re-read this thread, and appreciate that some of the points had been covered. In your response...

It is my belief that the information w.r.t. this design is incorrect, for these reasons: That by locating the PWM Mosfet in the Earth line, it can 'Modulate' the Hall Effect device, and that by so doing, produces a PWM signal on the Tacho. feed lead. I think that the (Intel) spec. requires the...