sbelectrics

Sorry about that; it's just that in the photograph it doesn't appear that the handle will pass the drill pillar. However, using your idea as the basis, I have now found a spare adjustable side handle from an old SDS drill which clamps nicely onto the knurled part of my pedestal drill chuck so that I can use that to do the same job in future. (The advantage of turning the outer section of the chuck is that it tends to increase the clamping force on the tap or drill as it is turned.)

Nice use of a drill press to avoid 'drunken threads' as our metalwork teacher used to call them. However, unscrewing the handle each time to move it around the chuck must be a bit of a chore? Could you not spring-load the handle so that it simply pulls out to move it around and the spring holds it into the hole in the chuck when released? (Or even just make the handle telescope in and out by about 5mm to enable pull-to-rotate and push-to-tap operation?)

You should probably mention that the individual lamps come in a range of voltages, from as low as 1.2V up to about 12V, and must match the one you are replacing, give-or-take about 10%, or it will be very dim or blow almost immediately.

A nice modern take on a constant current load I built with a 2N3055, a comparator and a potentiometer many years ago. With all that space inside the case and the built-in ventilation slots, wouldn't it have been tidier and safer to put the heat-sink inside? (The heat-sink can reach well over 100'C in operation.)

Nice idea. I wonder whether it would be possible to use a similar technique, but cutting a continuous spiral to form the bowl? It would make for a more interesting appearance.

Nice construction and a tidy layout, but weak on the maths: The R2 value of 48R can't be 18R + 38R. (Probably just a typo.)

Yes, the DeWalt unit does look expensive for the relatively low light output. Unfortunately, as I previously alluded to, both of the other lights you found contain constant-current drives so that they are not simple to dim without opening them and modifying the in-built circuitry.

Actually, the place you put the lamp (bulb) is technically known as a light fitting or luminaire.

A very nice toy, if somewhat expensive, time-wise.(BTW, shouldn't that be 'formerly' in your bio., not formally?

Sorry, I forgot to mention that I just used a multi-meter set to A/C mV or A/C mA connected directly across the coil for the tests.Regards,

Thank-you for your comments. I have modified the steps slightly to incorporate your suggestion and added some more detail. I have also re-done the measurements with the actual coil from a scrap Braun toothbrush, so that could be an international 'standard' for comparison.Regards,

A good reduce/re-use/re-cycle project. Since this is a stereo radio, and there appears to be space for two 'speakers, why not fit two side-by-side? If you have the choice, a regulated power supply would give better sound quality with less 'hum.'

Rather than squeeze the ball, could you not suck the air out with a hypodermic needle and a vacuum pump? The ball should collapse under atmospheric pressure to ease insertion. The blemish would then be completely invisible and the ball would be fully usable if removed from the bottle.

I like the idea of an infra-red extender, but think this is unnecessarily complicated, decoding then re-sending the signal, and will only work with the selected protocol. Would it not be simpler to use an IR detector, amplify the signal, and send it down a pair of wires to an IR emitter in the room(s) with the device(s) you wish to control? This would then work with multiple IR controllers and receivers in any number of rooms.