| Products > Test Equipment |
| UNI-T UT61E Multimeter teardown photos. |
| << < (186/217) > >> |
| Hydrawerk:
The bargraph disappears and appears again. This is weird. |
| nyarvin:
One thing to note about the new PCB layout, as regards adding protection elements: there are four places to add MOVs (or gas discharge tubes), but the way they are connected is not simply as shunts to ground. Instead, one of them shunts to ground and then the other three connect to it. So if you just stick one-kilovolt MOVs in all of them, they may not fire until the input reaches two kilovolts. Instead, for a kilovolt of protection, use 500V MOVs everywhere, or three one-kilovolt MOVs plus a jumper in the fourth place. Also, besides those four places, there's another unpopulated space for a MOV near the current-measuring stuff. |
| joeqsmith:
I picked up a brand new UT61E. It appears identical to the one 5KY had sent. Metal can and all. So, what I would like to do if modify this meter with the MOVs people are recommending, or use the parts that are available in the one being supplied to Germany. I will then retest it to failure and see if there are any improvements. Keep in mind the 61E and D never made it to the mini surge test. They both failed ESD with that little grill starter. |
| jarvis:
--- Quote from: Hydrawerk on May 20, 2016, 08:30:26 pm ---The bargraph disappears and appears again. This is weird. --- End quote --- The bar-graph is shown by the measurement time counting down for mF range of CAP. It is indicated in datasheet of ES51922 chip. |
| MosherIV:
Hi --- Quote ---So, what I would like to do if modify this meter with the MOVs people are recommending, or use the parts that are available in the one being supplied to Germany. I will then retest it to failure and see if there are any improvements. --- End quote --- Look at this thread https://www.eevblog.com/forum/testgear/varistormov-for-ut61e/ I have just got these http://cpc.farnell.com/epcos/b72210s0381k101/varistor-40-0j-385vac/dp/RE03689 to fit in mine. Have not fitted them yet, I want to check the capacitance measurement before and after - I will only have access to a LCR bridge at the weekend to check the 1% caps, that I just bought, against the meter readings. These http://cpc.farnell.com/epcos/b72214s0321k101/varistor-84-0j-320vac/dp/RE03698 Will give you a lower clamp voltage but not give you the full 1000V DC spec |
| Navigation |
| Message Index |
| Next page |
| Previous page |