| Products > Test Equipment |
| 40,000 Count Multimeter under $50 - HoldPeak HP-770D |
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| LooseJunkHater:
--- Quote from: iMo on September 13, 2023, 07:10:13 am ---Something like this.. --- End quote --- Exactly, except I'd personally do 2s (one lithium cell in each aa battery slot) due to the device using a (per video) 3.5v linear regulator. |
| magic:
--- Quote from: iMo on September 12, 2023, 09:36:58 am ---A pity they use the 9V block battery when the Vreg is 3.3V one inside, it takes 5.6mA (backlit leds off) what is not particularly low for a, say, 9V 250mAh NiMH battery, imho.. --- End quote --- :wtf: Now, this was probably the main reason I disliked it. Very wasteful, lousy battery life. --- Quote from: LooseJunkHater on September 12, 2023, 02:28:23 pm ---I actually think it's kinda nice that it uses a 9v battery with a 3.3v regulator. It allows the meter to be easily modded to use rechargeable lithium batteries in a 2s configuration. It'll have a longer battery life compared to the 9v cell and be rechargeable. --- End quote --- I would even consider single cell. The regulator is probably LDO and IIRC Li-ion delivers almost all its charge at more than 3.3V. The "battery low" indicator would need to be modded either way, because it reportedly trips at 8V. |
| LooseJunkHater:
--- Quote from: magic on September 13, 2023, 07:04:25 pm ---The "battery low" indicator would need to be modded either way, because it reportedly trips at 8V. --- End quote --- I'd imagine it's just a simple voltage divider. Considering how few components exist on the PCB, I couldn't imagine this will be problematic to locate and modify. |
| GigaJoe:
--- Quote from: LooseJunkHater on September 13, 2023, 03:20:07 pm ---Can I essentially use any crystal which is faster than the original? --- End quote --- certainly, some dmm has 2 chips and 2 crystals - don't recommend touch those , most likely fail |
| LooseJunkHater:
--- Quote from: GigaJoe on September 14, 2023, 03:09:34 pm --- --- Quote from: LooseJunkHater on September 13, 2023, 03:20:07 pm ---Can I essentially use any crystal which is faster than the original? --- End quote --- certainly, some dmm has 2 chips and 2 crystals - don't recommend touch those , most likely fail --- End quote --- https://www.hycontek.com/wp-content/uploads/DS-HY3131_EN.pdf Page 20 of the schematic does make mention of an internal crystal oscillator. I wonder if the internal crystal oscillator has been disabled for this product so that an external one is used instead? |
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