Tag Archives: smd

Joule thief AA battery led circuit

Here I present to you a single AA battery led circuit. This circuit is a variant of the Joule thief in that it contains 2 transistors and a simple standard 2 lead inductor instead of a hand wound 2 wire inductor.

white led circuit joule thief detail

You can use it as a white led torch. You can use a fresh AA battery, but the circuit is special in that it accepts empty batteries. Down to 0.7 volts. Do you have a box of empty batteries? They are still useful to power this led circuit. Continue reading

Random timer circuit using a Attiny24A

This random timer circuit is based on a Atmel ATTINY24 avr driving one power relay. You can use this circuit to switch on and off other circuits randomly. For example, when using this circuit on a model railroad you can turn on and off parts of the animated or moving scenery to create a more dynamic view.

attiny24 random timer circuit prototype

This circuit was designed to be used on a modular model railroad. This model railroad contains different flashing light on ambulances, police cars and fire engines. These lights are on all the time, with this circuit I hope to keep visitors of a model railroad exposition more interested while watching all the action. Continue reading

7-segment led clock building progress

I made some progress with building my led clock.  In the video you can see 80 74hc595 shift registers driving 80 7 segment led displays. The bottom row works, but has no data yet to display. You can see: unix timestamp, day of week, weeknumber, date, new earth time, swatch internet time, hexadecimal time, French revolution decimal time, approximate local solar time and local time.

7 segment led disply with 74hc595

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