Digital Potentiometer Using Optical Rotary Encoder & LS7184

The primary application of the project is to replace the mechanical potentiometer with optical encoder which is long life, accurate, smooth in operation. The simple project has been designed around LS7184 quadrature clock converter IC from LSI semiconductor, AD5220-10 Digital potentiometer from Analog Devices, and optical encoder from Burns.

Quadrature clocks derived from optical encoder, when applied to the A and B inputs of the LS7184, are converted to strings of Clock and an Up/down direction control. These outputs interfaced directly to AD5220-10 Digital potentiometer IC.

The AD5220-10 contains a single channel, 128 positions, and digitally-controlled 10K ohms variable resistor (VR) device. This device performs the same electronic adjustment function as a potentiometer.

Jumper J1 provided for scale of the 3-state input to select resolution x1, x2 or x4. The input quadrature clock rate is multiplied by factors of 1, 2 and 4 in x1, x2 and x4 mode, respectively, in producing the output UP/DN clocks. x1, x2 and x4 modes selected by the MODE input logic.

levels are as follows:

Mode = 0 : x1 selected

Mode = 1 : x2 selected

Mode = Float : x4 selected


  •     Supply 5V DC
  •     J1 Encoder pulse multiplication ( Jumper JL Close =1X, Jumper JH Close = X2, J1 Open = X4)
  •     Header Connector for Supply and Output
  •     Potentiometer Resistance 10K Ohms
  •     R5 Resistor For Programmable output pulse width (200ns to 140μs) – Read Data Sheet
  •     X1 , X2 and X4 mode selection
  •     Excellent regulation of output pulse width
  •     On-chip filtering of inputs for optical or magnetic encoder applications.
  •     TTL compatible I/Os

Note : Input for external component connection. A Resistor (R5) connected between this input and VSS adjusts the output clock pulse width (Tow). Refer to graph for appropriate bias resistor value.

















The Tiny Audio Amplifier MODULE  is a good choice for battery operation. It is based on  LM386 IC, useful in various applications like robotics, science projects, intercom, FM radio and many more.

  • Power Supply 6V-9V
  • 300mW Output @ 8Ohms Load
  • On Board Potentiometer for Audio Level Adjust
  • Header Connecter for Supply, Signal in and Speaker
  • On Board Power LED
  • Input: Standard Audio Signal







Digitally Controlled Analog Microphone Preamplifier Using PGA2505

The project is based on PGA2505 which is a digitally controlled, analog microphone preamplifier designed for use as a front end for high performance audio analog to digital converters (ADC). The PGA features includes low noise, wide dynamic range, and a differential signal path. An on chip dc servo loop is employed to minimize dc offset, while a common mode servo function may be used to enhance common mode rejection. PGA2504 features a gain range of 9dB through 60dB (3dB/Step) , along with unity gain setting.


Universal Dual Op-Amp Development PCB & Schematic using THT Components

The Universal Op-Amp Development board is a general purpose blank circuit boards that simplify prototyping circuits for a variety of Op-Amp circuits. The evaluation module board design allows many different circuits to be constructed easily and quickly.

Universal Dual Operational Amplifier (Op-Amp) board is designed to aid in the evaluation and testing of the low voltage/low power and some precision operational amplifiers. This board will accommodate Dual op amp that are assembled in a 8 Pin Dip package. This board is designed to use single or dual amplifiers. Many different circuits can be made such as inverting, non-inverting, differential-In amplifiers and low-pass, band-pass, band reject, or notch second order filters. The amplifier can be powered with single or dual supplies. These circuits can be configured without any modifications to the board, all that is necessary is to select the correct resistors and capacitors. The other optional components can be left open or shorted depending on the configuration desired.

Power is applied to the Header connector pins labeled VCC,-VEE, GND, If a single supply is used, then -VEE should be connected to GND.

This board mainly support lots of Texas instruments Op-Amps, On Semi, Analog Devices

List Of Op-Amps Can be use

  • OPA2350
  • OPA2340
  • LM358
  • LF422






Inverting Operational Amplifier Circuit ( Universal Op-Amplifier Development Board)

This is most widely used operational amplifier circuit.  It is an amplifier whose closed-loop gain is set by R27 & R18. It can amplify AC or DC Signal.

Non Inverting Operation Amplifier ( Universal Op-Amplifier Development Board)

This simple circuit is a non-inverting Operation Amplifier can be made using universal Op-Amplifier Development Board. Output voltage has same phase as the input voltage ( For DC Input)

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