Products > Test Equipment
ET5410 added external sense with BNC
andyB2022:
Hi! As I've saw here on the forum another colleague modified his East Tester Electronic load to have external sense capability, so I've thought to do mine too. The overall job is very easy, just buy a DPDT switch and a BNC connector in my case (it's more versatile than just 2mm banana female plugs imo..). Hardest part is getting the holes drilled and aligned as best as possible with the oem banana plugs. Now this 200$ thing can beat with 1k$ loads out there (as functionality and not precision in measurements) Enjoy the photos!
DaneLaw:
Interesting..well done :-+ just took the plunge today on the ET5410
after been eying these budget electronic loads for some years, and if I actually needed an electronic load .
was unsure if it should be ET5410 (old gen) or UnitT UTL8211 or DCL6104 or ET5410 (new gen) that looks like a revision of the DCL6104, or UTL8211.
Kunkin184 was not in the picture, simply down to the 7segmented display, which can be quite cumbersome for a unit with certain features, settings, and overview - even though the inner hardware does seem quite solid with the price in mind.
Landed on the ET5410 (old gen) from EU stock, as it was the cheapest and seems to do as intended, and as far as I could tell, there was nothing that stood out, versus any of the other LCD variants' to add another +35% in cost.
andyB2022:
You won't regret it. :-+
Curious:
Hello AndyB,
Beautiful job on the upgrade!
Before I snip the green & blue sense wires, I'm wondering if the sense wires MUST be connected to either 1)original Banana jacks or 2) external source DUT? In other words, if I did the new pair of small banana plugs approach, MUST there be sense wires to the source DUT or original Banana jacks? You used a DPDT switch suggesting that this is true.
Thanks!
mawyatt:
One needs to be very careful about opening the feedback with cuts/opens, this could cause unknown feedback which may drive the controlling loop to the rails, and maybe even cycling between the rails with disastrous results to the DUT and load.
Without a verified schematic, a safer approach would be to place small (100~1K) resistors across the cuts/opens so when nothing is connected by the sense wires or they aren't used but switch is in the remote sense position, then the resistors still provide some feedback across the cuts/opens, maybe with a slight error. When the switch is in the remote sense position the resistors are effectively shorted by the sense leads and have little to no effect, and when the switch is in the normal direct sense the resistors have no effect since they are directly shorted by the switch.
IMO this is a much safer approach and costs almost nothing, we would never implement a feedback sensing capability, nor modify for such, without the ability to keep some level of remote sensing feedback in effect in all cases, even when the sense wires are not used, fall off, or open, and the system is setup for remote sensing.
This is basically a fail safe approach as high gain negative feedback systems (like these electronic loads) can do nasty things when the feedback is opened, even momentarily!!
Anyway, we do like the addition of the remote sensing capability, and the use of a BNC is a nice touch :-+
Best,
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