Comments on: EEVblog #102 – DIY Constant Current Dummy Load for Power Supply and Battery Testing http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/ Durable Laptop Batteries Tue, 30 Apr 2013 01:48:43 +0000 hourly 1 http://wordpress.org/?v=3.5.1 By: JTGaming http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16999 JTGaming Sun, 26 Aug 2012 09:08:03 +0000 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16999 Hi! I need to build a dummy load for a PC power supply that can draw up to 100A and another unit that can draw up to 30A that are adjustable in steps of 10A and 5A respectively. I know my basic electronics but I would have absolutely no idea on where to start with this. I have heard MOSFETs are very scalable and can achieve this? with adequate cooling, but I need a circuit diagram or something so I can make it. Please help!

]]> By: r0ger0001 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16998 r0ger0001 Sun, 26 Aug 2012 08:24:12 +0000 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16998 How many ampere is the max? discharge for this design?

]]> By: 0sys0 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16997 0sys0 Sun, 26 Aug 2012 08:19:01 +0000 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16997 How to determine the require gate voltage in order to obtain 1v source voltage?
is there? any source available?

]]> By: kildas http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16996 kildas Sun, 26 Aug 2012 08:11:55 +0000 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16996 DaveCAD ? :D Where can i download it?

]]> By: leeYT321987 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16995 leeYT321987 Sun, 26 Aug 2012 07:34:29 +0000 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16995 Thanks a lot Dave.
What? is the use of the extra op-amp?
Why does the MOSFET need to be logic-level?

]]> By: joshstube http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16994 joshstube Sun, 26 Aug 2012 07:05:34 +0000 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16994 Great Idea Dave!
I want to build one!

A request:
Please add 17:17 to the next “how to entertain a geek Highlights!
Especially the part? about doing it with “intelligent control” ;)

]]> By: Axel Werner http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16993 Axel Werner Sun, 26 Aug 2012 06:20:01 +0000 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16993 Aint there no way to have a variable “artificial” load without the need of power resistors? in series?? some semiconductor that burns all the heat just into the cooler and not into the power resistors?

]]> By: aseglkj http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16992 aseglkj Sun, 26 Aug 2012 05:39:32 +0000 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16992 of course … all you need is an opamp like an lm358 that controls a large n-fet, like an IRFP460, source grounded via? a current measuring shunt. you feed the voltage from the shunt to the inverting input and a reference voltage to the noninverting input. you connect the positive of the DUT to the drain of the fet and the negative to ground. you can power the circuit from a 9v battery, the whole device draws only a couple mA.

]]> By: thenaimis http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16991 thenaimis Sun, 26 Aug 2012 04:54:34 +0000 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16991 Pretty awesome little project. I want to make one but I think I’d like to “crank it up a notch” and have a? microcontroller involved that varies the current, takes measurements and spits them out back to a computer. Press a button, capture data and graph :-) . The original use of your board seems to do something along those lines where the uC controls the current, unless I misunderstood.

]]> By: EEVblog http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16990 EEVblog Sun, 26 Aug 2012 04:24:07 +0000 http://blog.laptopbatterylife.com/2012/08/25/eevblog-102-diy-constant-current-dummy-load-for-power-supply-and-battery-testing/#comment-16990 Correct, that’s what the original board does. Micro with constant? current/resistance/power and logging capability.

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