Reddit:Electronics

In ireland we call rain sensors outdoor normally closed switchs

Here's the method I use for renewing crusty soldering tips. If you keep yours cleaned and tinned, you shouldn't have to do this often if at all.

Forgive my dirty workbench.

You will need: * Power drill * High grit sandpaper (300, 400, 600) * Rosin core solder, or a can of tip tinner

Remove the tip from the iron and mount it in your drill. Do not overtighten; hand tight should be sufficient. (Picture 2)

Try a higher grit before using a lower one. This one wasn't bad so I started with 400 (picture 3)

After several passes with one grit, move to the next higher and continue polishing. (Picture 4) 600-800 should be fine for most.

Once your tip is clean and shiny, clean it with a solvent (isopropanol, acetone, etc) and mount it in your iron. Do not contaminate the tip with oils from your fingers. Clean it again once it's in the iron, if you have to. (Picture 5)

If you are using the solder method, clean a length of solder and wrap it tightly around the tip. You only need one layer, and you do not need to wrap the entire shank; only the plated surface should be wrapped.

Set your iron to operating temperature and let it warm up (Picture 6)

If using solder, the solder should melt and tin your tip.

If youre using tip tinner, drag the tip across the tinner while turning it slowly. (picture 7)

Use brass wool to gently wipe the tip clean, and re-tin using a small amount of solder. (Picture 8)

Your tip is now ready for use. If storing it make sure you keep it tinned. The shank will quickly become discolored again from oxidation and burning volatiles; this is normal, but you can clean it if desired with mild steel wool or high grit sandpaper.

Alarm that counts using a 7-segment display. Added the ability to use a single scr to latch and power an led with a battery, since the most important element is to have a way to know whether someone is inside waiting to do you harm. A single led accomplishes this. Here's the pcb, and Photoshop even gives me the ability to label it. I simple head over to my local library, and have them print this onto this special paper with their laser printer, and then iron & etch it.

https://i.redd.it/16nes7xdttwd1.gif

Wanted to share my experience with getting multicolour PCBs fabricated and the results. To try is out I just made e a simple badge..

The image was created in Inkscape and exported as a ping..

Then just sent the png along with the Gerber's for fabrication.

The results are excellent!!

https://github.com/TannerNelson16/sprinkler_controller

Not sure if this belongs here, but this was originally mostly a software project that's morphed into a little bigger project. It's currently open source, but I may look into selling complete units in the future. Currently designing the enclosure for this unit.

Features:

• MQTT compatibility (Works with Home Assistant)
• Micropython on ESP32 controller
• Web Server (Configurable via IP Address)
• Maintains Operation Regardless of maintained connections. Will broadcast an Access Point if necessary
• 24VAC input with Custom Voltage Regulator and input capacitors to mitigate ripple from the full wave rectifier
• LED power Indicators

https://preview.redd.it/yr0xq0jdqdvd1.jpg?width=4032&format=pjpg&auto=webp&s=0decb64ef085baee13b635ccc5ed2d1cf6fbe0f2

(I still have to install the remaining LED indicators and the other resistor network if you're confused by the image. Just wanted to get everything tested.)

Made some mistakes in the design, but got them sorted and now I’m very happy with the final results!

Its using ECC83/12AX7A/5751WA Tubes which require 6.3V at 0.6A for heating. This Op-Amp requires +300V and -300V on its rails and has an output voltage swing of +50V to -50V. Its input offset voltage is 2.4V for it to detect a difference.

Here its wired up as an inverting amplifier with a gain of 10. Both probe leads are x10 probes, top channel is the output (5V/div -> 50V/div) and the bottom is the input (0.5V/div -> 5V/div) So I get a gain of 10 and it inverts, just as expected.