0
\$\begingroup\$

Let's say I put in an endoscope like camera with the lens at the inside edge of the box and the wire behind metal sheet. Here's a mockup:

poorly made diagram

Possible idea: The lens is behind a holes but the hole is directly in front of lens. The lens would be facing inwards to the center from the edge of the cube. This does not seem sufficient as the radiation is being reflected off the walls so it's fairly random. Is there anyway to make it microwave safe for recording while microwave operates?

I watched some microwave tear down videos and it seems like (on a surface level view) most of the electronics are safely just hidden behind a wall. That to me suggests the heat build up isn't too high or the electronics are designed to be heat resistant. In this case the lens/camera is exposed to the radiation..

If you have any ideas/thoughts on how the lens/electronics of the camera can be protected from microwave radiation while having full view of the plate, I would appreciate hearing them.

The thought driving the question is: Would an endoscope like camera be safe from microwave radiation/energy behind the inside microwave box?

\$\endgroup\$
  • 1
    \$\begingroup\$ Do not modify the cavity. Let the camera peek through one of the existing ventilation holes. \$\endgroup\$ – Neil_UK Jun 18 at 7:08
2
\$\begingroup\$

This is a very dangerous idea. Your questions and your diagram show the potential for you or someone to get badly hurt.

The only safe way is to place the camera outside the unmodified microwave oven. Make a hood to screen out ambient light. Buy a microwave with a black coloured screen instead of a white one. But don't go modifying the microwave.

Some more detail if you are not convinced:

  1. Your diagram shows the camera poking through a hole. Don't do this! A quarter wave, or 3 cm of wire, will form an effective antenna and transfer most of the power of the microwave, to the cable! This will not just damage the camera and the phone/computer, it could injure you if you're holding it, or standing very close.

  2. You will notice that there's a gap between the punched metal window and the clear plastic window. This is because there are evanescent waves extending about one hole diameter, out of each hole. The plastic stops you getting too close. Don't put the camera touching the surface of the metal.

  3. Microwave ovens are full of dangerous voltages. What happens when your glue comes loose or a child trips on the USB cable and it falls and touches the high voltage terminals inside? The whole phone or computer could be charged to a dangerous voltage, you could kill yourself (Darwin award) or someone else (manslaughter). Don't go adding wires to the inside of a microwave oven.

  4. Metal doesn't magically shield the camera from microwaves. It needs to be continuously welded or cleaned and bolted down with an RF gasket. You can't make a shielded box for the camera, inside the cavity, without some way of welding it to the wall of the oven.

If you are looking for a way to design an oven with a camera port, for manufacture (after full safety testing) then there are ways of doing it safely. The 12 cm waves cannot pass through a waveguide smaller than cutoff so you could install a port or tube, perhaps 40 mm diameter and 150 mm long down which the camera could safely peer. There are ways of making the hole larger, even bigger than a wavelength, using specially designed chokes. These are used for conveyor belts running through microwave ovens for continuous cooking.

| improve this answer | |
\$\endgroup\$
  • \$\begingroup\$ Thanks Tom. The evanescent waves is one of my concerns, thinking back to High school physics (focus vs random light going into a fence (filter)). (2) I was thinking the camera could be behind the hold but even that feels suspect/inadequate safety measure. Your response is great as I do understand it's very dangerous hence my apprehension/questions. Waveguide seem interesting, yes Ideally the camera would be just a regular part of the microwave during manufacturing. (for my project/idea) . What could waveguide's be made of? I will be doing more reading on waveguides \$\endgroup\$ – tigertiger Jun 18 at 19:20
  • \$\begingroup\$ I would have to come up with a safe way to prototype, put it together and maybe get an electricians/electrical engineering buddies help \$\endgroup\$ – tigertiger Jun 18 at 22:16
0
\$\begingroup\$

Don't place the camera in the chamber. Place it outside with other oven electronics and let it peek through one of those holes in the wall.

But I would say keep an open heart towards burnt cameras. You may roast up one or two cameras before finding the way that works.

| improve this answer | |
\$\endgroup\$
  • \$\begingroup\$ I like that you guys are agreeing with this approach, gives me more confidence in it. Right now brain storiming possible faults and yeah I will have to order a few cheap ones to work it out. Thinking the camera body/wiring could benefit from microwave reflective material or thermal shielding as well \$\endgroup\$ – tigertiger Jun 18 at 6:08
  • \$\begingroup\$ I actually thought about placing the camera in the chamber while covered by some metal foil, but I think you know what happens when you put aluminum foil in microwave. \$\endgroup\$ – Abdullah Baig Jun 18 at 6:14
0
\$\begingroup\$

Microwaves can't pass through the holes. The holes in the metal walls of the microwave oven are intentionally made small enough that the microwaves cannot pass through them.

Arrange your camera so that it looks into the oven through one of the holes. It should be fine.


Be careful when you take the microwave oven apart. There are capacitors in there that are charged up to several thousand volts. They can hold a charge even when the oven is turned off and disconnected from the outlet.

Avoid putting your camera near the high voltage parts. If your camera is too close, it might get zapped by high voltage.

| improve this answer | |
\$\endgroup\$
  • \$\begingroup\$ thanks for the reminder, i will be rewatching the videos on teardown, do not want to die from this. Yes that's why i suggested the holes but I think over 1000s of uses, enough radiation may leak through the radiation coming is not from a focused source. radiation is around .12m which the holes should block out tho. Think it's worth wrapping the camera body/wire in a microwave reflective material? \$\endgroup\$ – tigertiger Jun 18 at 6:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.