Looking Mains Voltage In The Eye And Surviving | 220v Contactor Relay

I would build a custom circuit board, and not use soldermask on the heater side. Instead, I would bond a sheet of pyralux on the face of the heater. Pyralux is Kapton with integrated thermoset acrylic adhesive on one or both sides. 2 mil Kapton has a voltage standoff of 10KV, so electric shock would not be a problem. Bonding can be done in a standard oven using metal plates and clamps (to apply pressure), or with a special heated press.

I’ve thought about converting my Solidoodle 2 to 120v bed heating for ages now. I think it’s a good idea with a lot of benefits. I’ve been far to lazy to actually do it, however. Maybe one day I’ll get my act together. In the mean time I’ll just sit here and envy other people who have had the initiative to actually do it.

Another potential issue of the translucent mirror design is that with an extra optical surface between the lens and the imager, flare could be increased, and image quality degraded, and indeed we’ve seen some evidence of this in predominantly dark shots containing bright point light sources, as described elsewhere in this review. There’s also another surface for dust to adhere to, and while this would be too far from the image sensor to appear as distinct specks, it could further contribute to issues with flare and reduced contrast. While manual sensor cleaning will now be a familiar process for photographers used to shooting with a digital SLR, cleaning the pellicle mirror is a total unknown. The Sony A33 provides a cleaning mode allowing the sensor to be accessed, and the pellicle mirror itself can be manually raised to facilitate this, but Sony’s documentation provides no advice on cleaning the pellicle mirror itself, simply noting that the surface of the mirror shouldn’t be touched.

Retired engineer, 71 years young. Computer builder and programmer. Linguist specialising in language acquisition and computational linguistics. Interested…

That wouldn’t make things any safer, per se. It would give you an additional diagnostic datapoint as to which of the two 120V inputs has the reversal. But the primary symptom of a hot-neutral reversal is the angry buzz from the third relay combined with the third light not coming on.

The Sony Alpha A33 accepts both Memory Stick Pro Duo / Pro-HG Duo, and SD / SDHC / SDXC media, and is powered by an InfoLithium battery pack.

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Yes you are correct, I was remembering from just people recommending power USB power supplies, but looking at the latest data, it seems that current is always less than 215mA. That chip looks good.

One nice thing about the Sony A55 and A33′s electronic viewfinder is that the Fn menu is also available in the viewfinder display; you can make many camera settings without taking your eye from the viewfinder eyepiece. As I became more familiar with the camera’s controls, this led to a very efficient shooting style, although it would take more than the few days I’ve had with the camera thus far for this to become second nature.

For something like this I would go to a proper electrical supplier and probably would use an AC contactor relay that’s rated twice the current. Sure a contactor needs a 24V transformer but it’s a small price to pay and the current use would be insignificant compared the the hot water heater.

Like many things, it’s the few psychopaths who spoil it for the rest. For most people, it’s quite possibly an emotional disability.

I would also use a solid state relay. And I would think about gluing the glass plate with high temp silicone to the PCB. This vastly improves thermal contact and so heat transfer which reduces peak temp and thermal lag in the control loop. Also it prevents exposed live wires even in case the glass breaks.