Organize and Share your Electronics the way you want. Sign-Up for a free account now. It takes only 30 seconds!

12 Stage Neon Sequencer

12 Stage Neon Sequencer

This circuit is using 12 neon indicator lamps. It operates from 2 high capacity ni-cad cells 2.5 volts which keep it going for a couple weeks. High voltage 70 volts for the neon lamps is obtained from a small switching power supply using a 74HC14 Schmitt trigger squarewave oscillator, high voltage switching transistor, and 10 mH high Q inductor.
Most any small PNP transistors can be used that have a C/E voltage rating of 80 or more. The inverter stage (pins 5,6) is not needed and is just an extra stage. An adjustable low frequency oscillator made from two of the inverter stages generates the clock signal for the 74HCT393 binary counter. In this circuit, the timing capacitor should be non-polarized since the capacitor will charge in both directions, so two 6.8 uF tantalum caps were used back to back which yields about 3.3 uF. The 75K resistor in series with pin 1 limits the current through the input protection diodes when the capacitor voltage exceeds the supply voltage. This resistor may not be necessary with small capacitors at low voltage but was added as a precaution. The binary counts are decoded into 1 of 12 outputs by the 74HCT138 decoders and operates the same way as in the 28 LED clock circuit. The sequence can be extended to 16 by omitting the reset circuit and tying pins 2 and 13 of the counter to ground.

Visit Here for more.

 

More Articles to Read

Single-Sided USB Charger
Single-Sided USB Charger
A FPGA controlled RGB LED MATRIX for Incredible Effects – the Hardware
A FPGA controlled RGB LED MATRIX for Incredible Effects – the Hardware
Using Nanotimers to Reduce IoT System Power Consumption by an Order of Magnitude
Using Nanotimers to Reduce IoT System Power Consumption by an Order of Magnitude
Replace a microwave’s beeping with the Windows XP startup sound
Replace a microwave’s beeping with the Windows XP startup sound
A DIY Laser Scanning Microscope
A DIY Laser Scanning Microscope
Reverse-engineering the surprisingly advanced ALU of the 8008 microprocessor
Reverse-engineering the surprisingly advanced ALU of the 8008 microprocessor
ESP8266 LED lighting: QuinLED v2.6 PCB
ESP8266 LED lighting: QuinLED v2.6 PCB
Switching LVDS Graphics in a Laptop Computer
Switching LVDS Graphics in a Laptop Computer
Teleknitting: TV-based string art
Teleknitting: TV-based string art
DIY Bubble Machine
DIY Bubble Machine
Start your day with Nerf target practice!
Start your day with Nerf target practice!
Teardown of a Peaktech 6225A
Teardown of a Peaktech 6225A

Top




Shares