Search found 1727 matches

by ahull
Wed Feb 21, 2018 12:35 pm
Forum: Postbag
Topic: Andy's Postbag and random ebay links
Replies: 158
Views: 6432

Re: Andy's Postbag and random ebay links

Here is what you get for your twenty eight pence. 15V-MeterMechanism.jpg The mechanism is easily extracted from the case with a small pair of long nosed pliers. It is a friction fit, so no glue or tabs need to be dealt with. The resistor is conveniently soldered to two tabs, so easily replaced with ...
by ahull
Wed Feb 21, 2018 9:52 am
Forum: Postbag
Topic: Andy's Postbag and random ebay links
Replies: 158
Views: 6432

Re: Andy's Postbag and random ebay links

... and something extra south of the cross-roads.... There was quite a lot of "extra" stuff going on in that neck of the woods back in the seventies and eighties, just at the other end of Bond St, or so I'm told :P , which would explain the need for the cop shop. :o Its all been "gentrified" recent...
by ahull
Wed Feb 21, 2018 9:14 am
Forum: Off topic
Topic: UT61E SD BLE logger
Replies: 6
Views: 93

Re: UT61E SD BLE logger

If you are using Linux, you might find these useful. http://www.mtoussaint.de/qtdmm.html#description https://github.com/pingumacpenguin/QtDMM-DTM0660-Version/blob/master/README.md https://sigrok.org/wiki/Multimeter_ICs .. actually they are also useful even if you use Windows, since you can use the c...
by ahull
Tue Feb 20, 2018 11:58 pm
Forum: Postbag
Topic: Andy's Postbag and random ebay links
Replies: 158
Views: 6432

Re: Andy's Postbag and random ebay links

picture hasn't :) looked at the ebay link, last time i saw something like that was in a Henry's Radio advert, Practical Electronics/Wireless or similar. Edgeware Rd, what was that road in Soho also with lots of electronics shops ? always to over explain my visiting it :lol: srp Picture fixed. I use...
by ahull
Tue Feb 20, 2018 10:13 pm
Forum: Postbag
Topic: Andy's Postbag and random ebay links
Replies: 158
Views: 6432

Re: Andy's Postbag and random ebay links

The uber cheap moving coil meters I bought arrived. Meter.JPG The resistor is 6.2kOhm (measures at 6.09kOhm) Total resistance of meter incl. resistor= 6.31kOhm and FSD is 25V, so I=V/R so I calculate the current through the movement needed to get FSD to be 0.003961965A or around 4mA Measured interna...
by ahull
Tue Feb 20, 2018 8:55 pm
Forum: Projects
Topic: LSE RTC calibration
Replies: 9
Views: 155

Re: LSE RTC calibration

You cannot beat the DS3231... Perhaps not.. but that does sound like a challenge that might be worth investigating. The DS2321 states the following in the datasheet. Accuracy ±2ppm from 0°C to +40°C Accuracy ±3.5ppm from -40°C to +85°C .. so I think we are already well within that ballpark, even be...
by ahull
Tue Feb 20, 2018 10:41 am
Forum: Projects
Topic: LSE RTC calibration
Replies: 9
Views: 155

Re: LSE RTC calibration

Would a correction factor based on the temperature of the chip (read from the on board temperature sensor) improve the accuracy still further? I'm thinking of something along the lines of a TCO style correction where you place the crystal in thermal contact with the processor, or even add a small re...
by ahull
Mon Feb 19, 2018 4:35 pm
Forum: Off topic
Topic: UT61E SD BLE logger
Replies: 6
Views: 93

Re: UT61E SD BLE logger

by ahull
Sun Feb 18, 2018 11:49 pm
Forum: Code snipplets
Topic: Reading Battery Voltage
Replies: 4
Views: 138

Re: Reading Battery Voltage

Do you switch off/on the bottom R2 divider resistor? I am using this circuit to enable the battery reading - I can't remember where I found it but it works well for me. Any suggestions on improvements to my code or circuit is always appreciated! That looks like a pretty useful and simple power mana...
by ahull
Fri Feb 16, 2018 1:00 am
Forum: Off topic
Topic: I.C. Tester
Replies: 3
Views: 108

I.C. Tester

This was on HAD, and reminded me of a similar gadget I had years ago (which came as a DIY kit for an ISA card for a Windows 95 PC from memory).

http://www.instructables.com/id/Smart-IC-Tester/

I wonder how easy it would be to port to the STM32F103XX