Neon Blinky Lights

When ever I descibe what I do for a living to people that aren't very technical, I just say "I make lights blink"... which isn't that far off from the truth.....

Last week I dug out an old Analogic AN3100 Precision Voltage Source out of the scrap pile at work.  I love tearing apart old test equipment; especially stuff that was last calibrated the year I was born :)

The display had a couple neon bulbs that were burnt out, but everything else looked in good order.

A little searching on ebay, a week and $2.50 bucks later I had 10 brand new neon bulbs. I replaced the bulbs and this piece of test equipment is as good as new. This will come in handy with some of the home-brew ADC projects I am working on.

Since I had some extra neon bulbs left over I started playing.... I remember back to my first Electricity Class I had in High School. We made the worlds simplest Blinky Light. I strung together a couple bench PSUs so I could get +85VDC, grabbed a 220K Ohm resistor and a 1uF 250V cap. and made a blinky neon bulb RC circuit.

 The neon and the cap are in parallel and the resistor charges up the cap until the voltage hits the neon's voltage; the neon turns on and discharges the cap and the cycle starts all over.

A blinky light and I didn't even need a 555 timer.

I can't wait to show my two little girls when they get home.... Blinky lights are fun, and I am easily impressed, hopefully they will be too!