| Forum Home | ||||
| Press F1 | ||||
| Thread ID: 150022 | 2021-08-12 00:53:00 | Wifi from the mailbox? | Tony (4941) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 1479323 | 2021-08-22 21:53:00 | Maybe have a look at an optical switch like this one at Jaycar Photo Interrupter CAT.NO:ZD1901 to trigger a circut when something enters the box. It may work better than a mechanical one unless you keep spiders in your mailbox :) That looks like a neat idea, but I think I see some problems. The interruptible beam is between those two posts, right? In which case I think it would be difficult to position so that mail passed between the posts, and thick items such as magazines wouldn't fit. 11056 My current idea is to have a plate in the box on a pivot, so that when the mail arrives it causes the plate to swivel and depress the switch, so I don't have to actually attach anything to the switch. I need to do some experiments to find the optimum plate size and position so that it is always activated but still allows magazine-type stuff to drop without jamming. |
Tony (4941) | ||
| 1479324 | 2021-08-26 00:43:00 | I've come up against an interesting little problem with the microswitch. Ive created a plate which swivels when anything is placed on it, and I have it balanced so that it will move with the weight of a single piece of paper, then return to its original position. The problem is that the microswitch requires a surprising amount of force to actually activate it, and the movement of the plate is insufficient to do it except with something heavy like a magazine. An ordinary letter won't do it. I'm pretty much out of ideas. The only other thing I can think of is to have the switch mounted so the activator arm is vertically downwards, so the plate brushes against it when it moves. I'd have to modify it so it will won't just catch it on the way back up, but I think I can achieve that. Any suggestions? Doe anyone know how far the switch has to be depressed before it activates, i.e. is it as soon as it moves, or does it have to be pressed flat? |
Tony (4941) | ||
| 1479325 | 2021-08-26 01:19:00 | Lengthen the arm by joining it to a longer lever, thus giving more mechanical advantage. If you're sneaky you can do it with a piece of suitable wire wound round the existing lever to make it effectively longer. See here: www.google.com rp%2Fs%2Fis%2Fimage%2FGrainger%2F11X260_AS01%3Fhei %3D536%26wid%3D536&imgrefurl=https%3A%2F%2Fwww.grainger.com%2Fproduct %2FHONEYWELL-MICRO-SWITCH-Limit-Switch-Lever-Arm-11X260&tbnid=vJRAdJEa61yHpM&docid=I4Wm2hY_XjbMVM&w=536&h=536&q=lever%20microswitch%20arm%20extended%20to%20leng then%20lever Whenever I've used these lever switches I found that just by pressing them down slowly you can hear and feel when they activate. You could also measure it with an ohm-meter. |
zqwerty (97) | ||
| 1479326 | 2021-08-26 02:42:00 | Lengthen the arm by joining it to a longer lever, thus giving more mechanical advantage. If you're sneaky you can do it with a piece of suitable wire wound round the existing lever to make it effectively longer. That's pretty much the conclusion I'd come to. Of course there is only so much I can lengthen it before I run out of room in the mailbox... |
Tony (4941) | ||
| 1479327 | 2021-08-26 02:48:00 | By adding a weight to the wire you can make it more or less sensitive for any length of wire. Washers are a good thing to use or nuts if you need a bit more weight. | zqwerty (97) | ||
| 1 2 3 | |||||