This wasn't supposed happen - there I was happily sorting through my tools ready for a job tomorrow and my trusty old Kewtech KEW1700 voltage probe decided to exit the tool bag in two parts.
This is the test apparatus that I use for the test for dead procedure utilised to prove a circuit is de-energised before I start work on it. It does however have more functionality that a voltage probe and will test continuity, phase rotation and detect voltage on a single probe.
Kewtech KEW1700 Brochure. Kewtech KEW1700 Manual.
I am sure I put it in the tool bag in one piece? Must have been those pesky side cutters attacking it when I wasn't looking. Oh well, its useless to me now and will have to be replaced, may as well take a closer look at things!
The front is mostly shrouded by the faceplate for the LEDs that also houses the little buzzer and probe light button. The barrel at the top houses the two AAA batteries required to power it. Over on the left hand side you can just see the clip that connects to the probe within the housing. The other probe comes in on the lead on the right hand side and goes into the voltage dropper circuit.
It looks like the first component the lead goes to is an inductor and then the capacitor voltage dropper for AC voltage detection is next to it. On the opposite side the inductor feeds into a series resistor network in parallel with the capacitor circuit that looks to be the voltage dropper for DC voltage detection.
Not much going on underneath the LED housing, they are all surface mount LEDs with a lens cover over them, but you can now seen the probe connector much more clearly, the probe light button and continuity buzzer.
The component side reveals a few more surface mount components and the main chip. The main chip looks to be some type of microcontroller. Its main identification is 38003A40V, but is also stamped KEW 1710, so looks to be bespoke made / marked for Kewtech. There is a crystal there but I cannot make out its frequency. The other 8 pin chip is 285-12 which I believe to be a voltage reference, but am not sure. The rest of the components seem to be a mixture diodes, transistors, resistors and capacitors.
Looking back through my records, I seem to have purchased the Voltage Probe and Proving Unit as a pair back in 2010, so it has done a lot of work and definitely paid for itself. Looks like Have some shopping to do......
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