A Mixed-Signal LED Clock


Posted on Feb 6, 2014

The term `mixed-signal` is usually reserved for circuits and ICs that process both analog and digital signals. In that sense the title `A mixed-signal LED clock` is perhaps misleading since this is a digital clock from beginning to end. However, the readout is analog and since the beast had to be given a name, I a called it my `mixed-signal` clock


A Mixed-Signal LED Clock
Click here to download the full size of the above Circuit.

. Somewhere in the middle of the eighties, when I was studying, I joined the ECA: the Eindhoven Computer Association, a microcomputer club in Eindhoven. Although I am not a member anymore, they still exist and have now been active for more than 25 years [1]. Being situated in Eindhoven, the club obviously had close links with Philips, and regularly obtained surplus supplies of components of various kinds. I remember that these components could be bought for fl 0. 10 (10 guider cents) a piece on every Tuesday evening. At one time they had a batch of LEDs in various shapes and colors. In those days a LED was not quite the common component it is today. The availability of these LEDs in these beautiful colors and nice shapes suggested the idea for a clock with an analog clock face. Normally, I never bother about making a printed circuit board for my circuits. I prefer working on these cheap prefabricated pertinax breadboard cards. However, for the circular face of my LED clock I had no other alternative than to etch a PCB (Fig. 1). I made it in the summer of 1987, and after I had placed the LEDs and finished the wiring, I put it into a drawer. There it was forgotten due to more pressing projects (girls and examinations). Two years ago I found it again and decided to finish the clock. It actually became my first PIC processor project. The circuit of the clock contains no real surprises. A (literally) striking feature about this...




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

PIC controlled DDS VFO
18 LED sequencer timer
ultrasonic mosquito repeller
overtone crystal oscillator
coil coupled operation metal
Indoor Weather Station using Arduino
LED current limiter accepts ac or dc
Electronics Engineering Herald - online magazine of electronics -home
15 volts power supply electronic circuit project using LT3512
Direct Conversion AM Radio
Autotransformer decompression control circuit
DTL internal structure of the inverter circuit



Top