Makeshift load bank - Page 1
Forum section: electronics / testgear

author: Harrow
author_rank: Regular Contributor
timestamp: April 22, 2024, 03:08:30 am
content: Needed a load bank at short notice.Has anyone else done this? What other creative ideas have people come up with?

author: SeanB
author_rank: Super Contributor
timestamp: April 22, 2024, 05:53:23 am
content: Cup of cold water, TO3 package transistor and a resistor box. Solder leads on base and emitter, and bolt a lead to case. Then resistance box from collector to base, put in cup and turn up the wick to the desired current. Works so long as you keep filling the cup as it boils off.

author: tszaboo
author_rank: Super Contributor
timestamp: April 22, 2024, 10:36:04 am
content: Incandescent light bulbs were used for this. You can still buy 12V 20W halogen light bulbs by the dozen.

author: Hydron
author_rank: Super Contributor
timestamp: April 22, 2024, 10:43:38 am
content: Let me refer you to Mike's classic take on this:

author: BILLPOD
author_rank: Frequent Contributor
timestamp: April 22, 2024, 05:20:39 pm
content: I could only understand about every 3rd word; if speech was a tad slower,it might be a good video

author: shapirus
author_rank: Super Contributor
timestamp: April 22, 2024, 05:38:26 pm
content: Quote from: BILLPOD on April 22, 2024, 05:20:39 pmPfff those Americans!Can't even understand real English.p.s. it was one of those not very numerous videos where I didnothave to set the 1.25x or 1.5x playback speed :)

author: tautech
author_rank: Super Contributor
timestamp: April 22, 2024, 06:11:57 pm
content: For what load.....A 180A AC welder new to market we brought decades ago had to be subjected to 24hr loads to determine its duty cycle rating. Legislation required it.A heavy coil was wound and suspended in a 200l drum of water and welder dialed to max output for which the tester was required to keep the gently boiling drum of water full for 24hrs.The official duty cycle was determined by the max transformer core temp that in the case of this welder went 1oC above max for a 100% duty cycle rating.Testers were very disappointed to have to state the duty cycle as 40%, the only option when it missed 100% by 1oC.A little ingenuity can solve seemingly difficult problems.......

author: Demon Xanth
author_rank: Contributor
timestamp: April 22, 2024, 08:48:57 pm
content: We used 12V light bulbs at one place. Put 4 in series for a 48V supply. You can get a variety of "loads" and they can take a 100% duty cycle while providing a visual identifier if it's on. We also put a cover over them because they're really freaking bright when you're doing 5A@48V.

author: temperance
author_rank: Super Contributor
timestamp: April 23, 2024, 01:58:31 pm
content: Bulbs, especially halogen bulbs are very low resistance when cold. So it depends on what you want to test if a halogen bulb can be used.I'm not native English and I don't have any problem to follow Mike. The totally bonkers telly format fit for poor sods on crack on the other side of the pond drives most sane people nuts in less than 2 minutes.

author: elevendroids
author_rank: Newbie
timestamp: April 23, 2024, 04:08:47 pm
content: There's a recent video from Mr. Carlson's Lab where he used 5 industrial heaters for his 27kW load:

author: Phil1977
author_rank: Frequent Contributor
timestamp: April 24, 2024, 02:16:30 pm
content: A boost converter with a "frozen" regulation loop so that it always keeps the PWM user adjustable but stable and feeds all its output into a water kettle or lightbulb...It was just the easiest way for me to make a dumb load adjustable. And it´s load characteristic is not as crazy as a DCDC-converter in CV- or CC-mode.