Soldering iron accessory

My Yihua 936B soldering iron still works but one thing that I didn't like was that the handle would become uncomfortably warm.  It is a replacement iron assembly so maybe that's why ?  Anyway, I went back to the old Weller SP23 iron which works fine.

But one of the reasons why I abandoned the Weller in the first place was that one time I accidentally left it running, not quite sure how long, might have been days and days.  Luckily nothing bad happened but one nice feature of the Yihua is that when it reaches temperature there is a blinking red LED, so it's harder to leave it going accidentally.

mentioned this before:  https://wb9kzy.blogspot.com/2022/01/fighting-static-damage-part-3.html

The Weller doesn't have a switch or LED or anything, it just gets hot.  So I thought about adding a blinking LED to the iron.  I even breadboarded a 2 transistor oscillator to drive the LED.  But then I remembered that there are blinking LEDs on the market.  

I bought a couple from Mouser, not cheap at $1 each but I didn't want to buy on ebay and get zillions of blinking LEDs that I'd never use.

The first thought was to consider running the LED off the AC power directly.  But I actually bought some LED bulbs once that did this, a series cap was used - they did work but one of them literally exploded.  So I canned that idea.

Next I could add a transformer, rectifier and so on for a small power supply but then I'd need a box, ditched this idea too.

What about all those wall-warts that we all have ?  I dug out my box of them and they were all either broken or too big.

The idea would be to plug the wall-wart into a power strip (with switch) and then also plug in (and unplug) the iron as needed.

Finally I found the 21st century wall-wart, the USB charger.  Everyone has a pile of these as well.  I happen to have one with a permanently attached cord instead of the more common USB socket.  A bonus is that the USB charger plays nicely in the power strip: doesn't cover the next socket and the wire comes out the side.

I cut the mini-USB connector off the cord and then soldered the wires to the red blinking LED along with a 300 ohm series resistor.  The LED isn't that bright (neither am I) but it should be fine.

So now when I turn on the power strip the blinking LED goes ON and reminds me that the iron is connected.

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm