Printer Port 256 Relays 16K Dot Matrix

Advertise in delabs

Using this circuit on Printer Port, one could drive 256 Relays or 16K LEDs as Dot Matrix display. It can be used to drive a Large size multiplexed LED dot matrix display or Latched Relay-Solenoid-Motor-Lamp Array Drivers.

Printer Port 256 Relays 16K Dot Matrix – del20021

This circuit can be modified for a Static drive output or a fast changing output like a Waveform Generator. You can also make it a 16 Bit waveform generator. The frequency limited to the speed of the port or a fraction of it, depending on 8bit, 16bit or 32bit.

Printer Port 256 Relays 16K Dot Matrix

Now I have Some Explaining to do. Latch the U7 with a 8 Bit Data to address the device you want to talk to. So one among the 32 Output Devices can be Selected by a combination of G1-G2 of U5-U8 and U7 8 Bits, Split into Two Nibbles for Upper and Lower 16 Devices. That means 16 * 2 = 32 Devices of 1 Byte each,. 32 * 8 = 256 if my calculations are correct. Please verify.

One of the decoders U5 or U8 decode their respective nibble and output a Low on Selected device to Latch Data on the Chosen one (74HCT373). Why HCT ? Speed is good, low power and CMOS ! and works with TTL too. It Interfaced well for me on a Card with Both TTL and CMOS levels, with a Fast uC.

The 74HCT373 outputs are current amplified and isolated by darlingtons and optoisolators. Both source and sink examples shown.

This circuit was not tested and documented properly. So there may be things missing. It is just a Concept design..

More delabs Schematic Diagrams

  • Printer Port 256 Relays 16K Dot MatrixPrinter Port 256 Relays 16K Dot Matrix
    Using this circuit on Printer Port, one could drive 256 Relays or 16K LEDs as Dot Matrix display. It can be used to drive a [...]
  • Voltage Doublers and MultipliersVoltage Doublers and Multipliers
    Voltage multipliers are used to obtain low current high voltage, from an existing AC Source. Step up transformers can be used, but the insulation problems [...]
  • +5 to -5 using a 555 Astable Multivibrator+5 to -5 using a 555 Astable Multivibrator
    This is a very simple -5V supply using one 555, useful for analog blocks using FET Opamps using low power. This circuit came up when [...]
  • 3-1/2 Digit ICL7107 DPM Digital Panel Meter3-1/2 Digit ICL7107 DPM Digital Panel Meter
    This is a Digital Panel Meter based on ICL7107. This was the workhorse Digital Readout chip before Low power uC designs were developed. Even now [...]
  • Linearizing Circuit for ThermocouplesLinearizing Circuit for Thermocouples
    This circuit changes the gain of opamp U1B in four steps or segments. It can be used to get a linear output from most transducers [...]
  • Thermocouple Amplifier StandardThermocouple Amplifier Standard
    Thermocouple is the most common sensor in Industrial Temperature Measurement. The Signal Conditioning involves Cold Junction Compensation and High Gain DC Amplification. The output of [...]
  • Audio Visual User Interface with AckAudio Visual User Interface with Ack
    This circuit is an User Interface part of a Security Alertness Monitor that i designed decades ago. The circuits are here – Digital Circuits – Part 1 The RAM [...]
  • Tubelight Electronic ChokeTubelight Electronic Choke
    This is an electronic choke for a Conventional Fluorescent Lamp. This was an application note of MJE13005 a High Voltage Switching NPN Power Transistor. I [...]
About delabs 152 Articles
Product Design - Industrial Automation and Instrumentation. -