Solved - Witch DC Load - Maynuo 9812 or Itech 8512A+ - Page 1
Forum section: electronics / testgear

author: bingo600
author_rank: Super Contributor
timestamp: February 05, 2017, 07:15:49 pm
content: I have a 6632B that works as a "simple load" , but decided to get a real one.I'd like my new load to do 300W and 100+ volts / 30AI have been reading up on the DC loads here on the forum, and for my budget it seems like i should choose between:1: Maynuo 9712https://www.aliexpress.com/item/FREE-SHIPPING-Maynuo-M9710-DC-electronic-load-300W-150V-30A/32719309644.html2: Maynuo 9812https://www.aliexpress.com/item/FREE-SHIPPING-Maynuo-M9812-DC-electronic-load-300W-150V-30A/32722211925.html3: Itech 8512A+ - The + models seems to have the same readout as the Maynuohttps://www.aliexpress.com/item/FREE-SHIPPING-ITECH-IT8512A-DC-electronic-load-one-way-Programmable-150V-30A-300W/32521946782.htmlIt seems like i prefer the Itech , but have no real idea why, aestethics ??I think i read that the Maynuo can test a battery and cut off at a spcific voltage, while printing the energy deliveredCan the Itech do that ?The 9812 is $100+ more expensive than the 9712 , and i read that the LED feature of the 9812 is "useless"Why would one choose the 9812 over the 9712 ??Is there anything "must" the Maynuo can , that the 8512A+ can't ??Would the attached IF also work on an Itech ??Is there any new alternatives in the $400..$500 rangeTIA/Bingo

author: pelule
author_rank: Frequent Contributor
timestamp: February 05, 2017, 07:35:12 pm
content: I bought the Maynuo M9712B (0-15A, 0-500V, 300W) including the M133 isolated USB interface for $ 596 and quite happy with it.I decided for the 9712 because I need the higher voltage even the disadvantage of higher minimum impedance.

author: pe1oxp
author_rank: Regular Contributor
timestamp: February 05, 2017, 10:14:43 pm
content: When I bought my M9812 I wondered why it was cheaper then the M9712. I asked my seller what the differences where.They told me that they could make a better price because they placed a large order.I checked the price on the website (Eleshop.nl) and also now the M9812 is cheaperOff course the prices in China are good but what about taxes?

author: 2N3055
author_rank: Super Contributor
timestamp: February 05, 2017, 11:25:07 pm
content: I have Maynuo 9812 for some time and am happy with it..Very precise, good thermal design.. It came calibrated with calibration certificate.. I checked it and it was right on spot...Software is not half bad, all works as predicted..Took me some time to understand all the details form manuals but once you learn it it works great.Can recommend it.Sinisa

author: georges80
author_rank: Frequent Contributor
timestamp: February 06, 2017, 04:02:18 am
content: Been using my m9812 for a year+, gets used every few days and typically for hours on end. Other than one relay going sticky once (problem hasn't recurred since, but I have a spare relay on hand via digikey in case it ever does), it has been a reliable unit.Very accurate display. 4 wire mode works well. PC software is reasonable for a Chinese product. Made my own isolated USB interface module.cheers,george.

author: HKJ
author_rank: Super Contributor
timestamp: February 06, 2017, 06:50:13 am
content: I have been using a couple of the Itech loads for some time and they also works fine.Their interface protocol is nearly the same as the BK Precision loads (The battery test messages are different).

author: MikeLogix
author_rank: Contributor
timestamp: February 06, 2017, 07:02:57 am
content: That bottom image of the Itech looks a lot like my Keithley DMM.

author: georgd
author_rank: Regular Contributor
timestamp: February 06, 2017, 10:00:10 am
content: A question for new M981x users:On my new M9811 regardless of mode stays capital letterD.The version of firmware is 3.1LED.What is the meaning of this sign?Georg

author: 2N3055
author_rank: Super Contributor
timestamp: February 06, 2017, 11:08:18 am
content: Quote from: georgd on February 06, 2017, 10:00:10 amIt means it is in LED mode...LED mode is actually a mode for testing LED constant current switcher sources... It seems to have something with changing dynamic response to make it more stable with these kinds of sources..You toggle it with pressing <SHIFT> and <^> (cursor up) buttons.

author: bingo600
author_rank: Super Contributor
timestamp: February 06, 2017, 02:48:09 pm
content: Thanx for the ansvers guyzzI still like the Itech , and strangely it's cheaper then the M9812I'm using Linux , so i need to do my own scripting , and there it seems like the Itech Programming manual is a lot clearer than the Maynuo.I have been looking for the RS-232 DB9 pinout on the Itech , to see if it supplies 5v to the isolated interface on one of the pins.But can't seem to find any info.Can anyone verify that the Itech supplies 5v on one of the DB9 pins for the isolated IF ?The Maynuo seems to supply 5v on pin1 (see pic)/Bingo

author: HKJ
author_rank: Super Contributor
timestamp: February 06, 2017, 04:55:06 pm
content: My Itech manual do not list the pinout of the connector, but I believe all 3 loads (Itech, Maynuo, BK) uses the same interface connector and interface (IT-E132).

author: bingo600
author_rank: Super Contributor
timestamp: February 06, 2017, 05:11:37 pm
content: Thanx to allI just ordered the Itech 8512A+/Bingo

author: Fungus
author_rank: Super Contributor
timestamp: February 06, 2017, 05:46:39 pm
content: A witch load?Use it for testing you Halloween lights?

author: bingo600
author_rank: Super Contributor
timestamp: February 13, 2017, 07:00:02 pm
content: Got my load today ... Still climatizing.And my cable is still underway./Bingo

author: tecman
author_rank: Frequent Contributor
timestamp: February 17, 2017, 03:50:21 pm
content: I just got my 8512+. Very nice unit. Through Ali Express $ 407 shipped to US. hard to beatpaul

author: bingo600
author_rank: Super Contributor
timestamp: February 20, 2017, 10:57:01 am
content: I just got my cableTime for fun/Bingo

author: Mr. Scram
author_rank: Super Contributor
timestamp: April 09, 2018, 02:45:10 pm
content: Quote from: georges80 on February 06, 2017, 04:02:18 amHow does the 4 wire mode work? I only seem to see two terminals and I can't find any mention in the manual.

author: HKJ
author_rank: Super Contributor
timestamp: April 09, 2018, 03:13:29 pm
content: Quote from: Mr. Scram on April 09, 2018, 02:45:10 pmConnections are on the back.

author: maukka
author_rank: Unknown
timestamp: April 09, 2018, 03:16:44 pm
content: Quote from: Mr. Scram on April 09, 2018, 02:45:10 pmThe small -S/+S terminals in the back.

author: BillB
author_rank: Unknown
timestamp: April 09, 2018, 03:21:51 pm
content: In my 8511+ manual there is a paragraph about setting it up:Remote sensingRemote sensing is used to counteract the effect of lead resistance. For example, if youconnect a power supply to the DC Load, the voltage at the power supply's terminals willnot be the same as the voltage at the DC Load's terminals if there is a current flowingbecause of the finite resistance from the wires. Using remote sensing, you can sensethe voltage at the power supply's terminals, effectively removing the effect of the voltagedrop in the connection wire.When using remote sensing, the power displayed by the instrument includes both thepower dissipated inside the instrument and the power dissipated in the leads from thepower supply to the DC Load's input terminals.Steps to enable remote sensing in the menu:?1? Press (Shift)+ 9 key into the menu?2? VFD displays >CONFIG, press Enter key to confirm?3? Press to choose> SENSE, press Enter key to confirm(4) Press to choose>ON, press Enter key to confirm, then remote sense function hasbeen set,and VFD display Sense indicator.Remote Sensing: SENSE (+) and SENSE (–) are the remote sensing inputs. Byeliminating the effect of the inevitable voltage drop in the DC load leads, remote sensingprovides greater accuracy by allowing the DC load to regulate directly at the source'soutput terminals.

author: Mr. Scram
author_rank: Super Contributor
timestamp: April 09, 2018, 03:22:33 pm
content: Quote from: maukka on April 09, 2018, 03:16:44 pmI must be an idiot. I somehow found an image that apparently did not belong to a M9812. Thanks.