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.
















RC Signal Monitor Using 20 Bargraph LEDs Including RC Switch ( RC Signal Reader Using Bar-Graph Display)

The versatile Bar-Graph SMD components based R/C signal monitor & R/C switch is a great tool for R/C hobbyist R/C modeller and DIY robotics, Tiny Bar-Graph displays provide a Red color bright, easy to read display of Radio Control (R/C) signal from 1mS to 2mS.  This Bar-Graph has 20 segments in single color and display R/C signal in span of 1mS to 2mS. The Barograph RC Signal reader is based on PIC micro-controller PIC16F886. This high performance measurement provides unique capabilities and can be used in various applications like Radio Signal Monitor, Robotics, Machine Control, RC Remote Tester, RC Signal to ON/OFF switch by connecting Relay board or Solid state relay at output of any suitable LED. Multi switches also possible connecting relay boards on all separate LEDs. Solder Jumpers provided on bottom side of PCB to select particular output to interface with Relay or Solid state Relay. 

Note: This board has been designed for multiple options and has few extra components. Check BOM carefully before soldering the components.  Solder the parts as described in parts list. 



  • Supply 5V DC
  • Input 1mS to 2 Ms
  • Display Range 1.5mS to 2mS Center to Left 10 LEDs & 5mS to 1mS Center to Right 10Leds
  • Output Display 20 Color RED SMD LEDs
  • Compact Board with SMD Components
  • Supply input Header Connecter
  • Solder Jumper on each LED for Output Control, Alarm, and Relay














1.6KW Brush-Less Motor Power Driver Using IPM STK554U362

The compact motor drive power board is based on STK554U362A IPM module from ON semiconductor. It provides an affordable and easy-to-use solution for driving high power Brushless servo, AC Motors, and DC Brushless motors in a wide range of applications such as power white goods, air conditioning, compressors, power fans, high-end power tools and 3-phase inverters for motor drives in general.

The IPM itself consists of short-circuit rugged IGBTs and a wide range of features like (UVP) under voltage protection, (OCP) Over current protection with fault detection output flag , embedded temperature sensor NTC.Internal Boost diodes are provided for high side gate boost drive.

The main characteristics of this project are its small size, minimal BOM and high efficiency. It consists of an interface circuit, bootstrap capacitors, fault event signal and temperature monitoring. It is designed to work in single or three shunt configuration and with dual current sensing options: using three dedicated on-board op-amps

Thanks to these advanced characteristics, the system can provide the fast and accurate current feedback conditioning necessary for field oriented control (FOC). Refer Data sheet for more information


  • Input voltage: 125 to 400 VAC
  • Nominal power: up to 1600 W
  • Nominal current: up to 10 A
  • Input auxiliary voltage: up to 20 VDC
  • On Board 5V Regulator for Op-Supply
  • D2 Power LED (Gate Driver Supply)
  • 3 Pin Screw Terminal for AC Supply Input
  • 4 Pin Screw Terminal Connector For Motor Connections
  • On Board Fuse for Short Circuit Protection
  • Single- or three- shunt resistors for current sensing
  • IPM temperature monitoring and protection
  • Highly integrated device containing all High Voltage (HV) control from HV-DC to 3-phase outputs in a single small SIP module.
  • Output stage uses IGBT/FRD technology and implements Under Voltage Protection (UVP) and Over Current Protection (OCP) with a Fault Detection output flag. Internal Boost diodes are provided for high side gate boost drive.
  • 3 Independent shunt resistors and 3 X Channel signal condition amplifiers help to easy FOC based driver
  • Header connector provided for inputs and logic supply input
  • Externally accessible embedded thermistor for substrate temperature measurement.
  • Single control power supply due to internal bootstrap circuit for high side pre-driver circuit.
  • Externally accessible embedded thermistor for substrate temperature measurement.
  • All control inputs and status outputs are at low voltage levels directly compatible with micro-controllers.

Note : This board also supports following ICs





















TheSTK554U362A is Intelligent Power Module (IPM) based upon ONs Insulated Metal Substrate Technology (IMST) for 3-phase motor drives which contain the main power circuitry and the supporting control circuitry. The key functions are outlined below:




+, U-, V-, W-

These pins are connected with the main DC power supply. The applied voltage is up to the Vcc level. Overvoltage on these pins could be generated by voltage spikes during switching at the floating inductance of the wiring. To avoid this behavior the wire trac-es need to be as short as possible to reduce the floating inductance. In addition a snubber capacitor needs to be placed as close as possible to these pins to stabilize the voltage and absorb voltage surges.


U, V, W

These terminals are the output pins for connecting the 3-phase motor. They share the same GND potential with each of the high side control power supplies. Therefore they are also used to connect the GND of the bootstrap capacitors. These bootstrap capaci-tors should be placed as close to the module as possible.



These pins connect with the circuitry of the internal protection and pre-drivers for the low-side power elements and also with the control power supply of the logic circuitry. Voltage to input these terminals is monitored by the under voltage protection circuit. The VSS terminal is the reference voltage for the control inputs signals.


VB1, VB2, VB3

The VBx pins are internally connected to the positive supply of the high-side drivers. The supply needs to be floating and electrically isolated. The boot-strap circuit shown in Figure 20 forms this power supply individually for every phase. Due to integrated boot resistor and diode (RB & DB) only an external boot capacitor (CB) is required.

CB is charged when the following two conditions are met. ① Low-side signal is input ② Motor terminal voltage is low level

The capacitor is discharged while the high-side driver is activated.

Thus CB needs to be selected taking the maximum on time of the high side and the switching frequency into account.


The voltages on the high side drivers are individually monitored by the under voltage protection circuit. In case an UVP event is detected on a phase its operation is stopped.

Typically a CB value of less or equal 47uF (±20%) is used. In case the CB value needs to be higher an external resistor (of apx. 20Ω or less) should be used in series with the capacitor to avoid high currents which can cause malfunction of the IPM.



These pins are the control inputs for the power stages. The inputs on HIN1/HIN2/HIN3 control the high-side transistors of U/V/W, and the inputs on LIN1/LIN2/LIN3 control the low-side transistors of U/V/W respectively. The input are active high and the input thresholds VIH and VIL are 5V compatible to allow direct control with a microcontroller system

Simultaneous activation of both low and high side is prevented internally to avoid shoot through at the power stage. However, due to IGBT switching delays the control signals must include a dead-time.



For fail safe operation the control inputs are internally tied to VSS via a 33kΩ (typ) re-sistor. To avoid switching captured by external wiring to influence the module behavior an additional external low-ohmic pull-down resistor with a value of 2.2kΩ-3.3kΩ should be used.

The output might not respond when the width of the input pulse is less than 1μs (both ON and OFF).



The FLTEN pin is an active low input and open-drain output. It is used to indicate an in-ternal fault condition of the module and also can be used to disable the module opera-tion. The I/O structure is shown


The internal sink current IoSD during an active fault is nominal 2mA @ 0.1V. Depending on the interface supply voltage the external pull-up resistor (RP) needs to be selected to set the low voltage below the VIL trip level.

For the commonly used supplies VP:

VP = 15V -> RP >= 20kΩ VP = 5V -> RP>= 6.8kΩ


For a detailed description of the fault operation refer data sheet chapter 4


Note: The Fault signal does not latch permanently. After the protection event ended and the fault clear time(2ms) passed, the module operation is automatically re-started. Therefore the input needs to be driven low externally activated as soon as a fault is detected.



An internal thermistor to sense the substrate temperature is connected between TH and VSS. By connecting an external pull-up resistor to arbitrary voltage, the module temperature can be monitored. Please refer to heading 3.2 for details of the thermis-tor.

Note: This is the only means to monitor the substrate temperature indirectly.



Operation procedure

Step1: Please connect IPM, each power supply, logic parts, and the motor to the evaluation board,

and confirm that each power supply is OFF at this time.

Step2: Please impress the power supply of DC15V.

Step3: Please perform a voltage setup according to specifications, and impress the power supply

between the “+” and the “-” terminal.

Step4: By inputting signal to the logic part, IPM control is started.

(Therefore, please set electric charge to the boot-strap capacitor of upper side to turn on

lower side IGBT before running.)

* When turning off the power supply part and the logic part, please carry out in the reverse order

to above steps.

5A DC Motor Speed And Direction Controller Using MC33035

5AMP DC Motor speed and direction controller using MC33035 IC from on semiconductor, though the MC33035 was designed to control brushless DC motor , it may also be used to control DC brush type motors. MC33035 driving a Mosfets based H-Bridge affording minimal parts count to operate a brush type motor. On board potentiometer provided for speed control, slide switch for direction control and brake, On board jumper available to enable the chip. The controller function is normal manner with a PWM frequency of approximately 25Khz. Motor speed is controlled by adjusting the voltage presented to the no inverting input of the error amplifier establishing the PWM’s slice or reference level. Cycle by cycle current limiting of the motor current is accomplished by sensing the voltage across the shunt resistor to ground of the H-bridge. The overcurrent sense circuit makes it possible to reverse the direction of the motor, using normal forward/reverse switch, on the fly and not have to completely stop before reversing.

  • SUPPLY 12-18V DC
  • Load Up to 5Amps, 5Amps with large size heat sink on Mosfets
  • On Board Potentiometer for Speed Control
  • Slide Switch ( SW1) for Brake
  • Slide Switch (SW2) for Direction Control
  • Jumper (J1) Provided to Enable the chip
  • LED (D1) Fault Indicator
  • LED (D2) Power Indicator
  • CN1 , Supply 12-18V DC
  • MG1 Motor Connections








Step-Dir. signal to double drive CW/CWW Pulse Converter for CNC, Motion Control & AC Servo Driver

Simple Circuit converts Step/Dir. signal into to double drive CW/CWW Pulse, Mach3 and few Hobby CNC software’s provides Step/Direction pulse output to drive stepper motor drivers.

Various AC servo works with double CW/CCW pulse. This circuit is solution to interface such AC CW/CCW pulse based driver with Mach3 or other CNC software’s. Circuit designed around 7408 and 7404 IC, board support 5V or 24V supply. Open Collector output can be interface with 24V system by changing output resistors.


  • Supply 7V 24V DC
  • On Board Power LED
  • Inputs and Outputs Header Connector
  • On Board ERTH (Earth) Signal provided for chassis ground to avoid any noise


Note : Output Transistor can drive Stepper Drive or Servo driver Opto-couplers directly , choose appropriate collector resistor value for 5V or 24V


  • R3,R5,R9 470 Ohms for 5V DC Open Collector Output
  • R3,R5,R9 2K2 Ohms for 24V DC Open Collector Output



  1. Step Pulse ( TTL 5V)
  2. Direction Pulse ( TTL 5V)
  3. Enable Signal ( TTL 5V )



1 CW (5V Or 24V Open Collector)

  1. CWW ( 5V Or 24V Open Collector )
  2. Enable ( 5V Or 24V Open Collector )









4.5A H-Bridge DC Motor Driver Module Using TB6549HQ

The H-Bridge Motor Driver Module Based on TB6549HQ IC from Toshiba, is a full-bridge driver IC for DC motors that uses an LDMOS structure for output transistors. High-efficiency drive is possible through the use of a MOS process with low ON-resistance and a PWM drive system. Four modes, CW, CCW, short brake, and stop, can be selected using IN1 and IN2. Supply input 12V to 30V DC and Maximum Load 4.5Amps.

  • Power supply voltage: 30 V (max)
    Output current 4.5 A
    Low ON-resistance: 1.0 Ω (up + low/typ.)
    PWM control capability
    Standby system
    Function modes: CW/CCW/short brake/stop
    Built-in overcurrent protection
    Built-in thermal shutdown circuit













Dual Full-Bridge PWM Motor Driver with Brake Using A3968


The A3968 bidirectionally controls two DC motors. The device includes two full-bridges capable of continuous output currents of ±650 mA and operating voltages to 30 V. Motor winding current can be controlled by the internal fixed-frequency, pulse-width modulated (PWM), current-control circuitry. The peak load current limit is set by user selection of a reference voltage and current-sensing resistors.The fixed-frequency pulse duration is set by a user-selected external RC timing network. The capacitor in the RC timing network also determines a user-selectable blanking window that prevents false triggering of the PWM current-control circuitry during switching transitions.To reduce on-chip power dissipation, the full-bridge power outputs have been optimized for low saturation voltages. The sink drivers feature the Allegro® patented Satlington® output structure. The Satlington outputs combine the low voltage drop of a saturated transistor and the high peak current capability of a Darlington.For each bridge, the INPUTA and INPUTB terminals determine the load-current polarity by enabling the appropriate source and sink driver pair. When a logic low is applied to both INPUTs of a bridge, the braking function is enabled. In brake mode, both source drivers are turned off and both sink drivers are turned on, thereby dynamically braking the motor. When a logic high is applied to both INPUTs of a bridge, all output drivers are disabled.Special power-up sequencing is not required. Internal circuit protection includes thermal shutdown with hysteresis, ground-clamp and flyback diodes, and crossover-current protection.

  •     ±650 mA continuous output current
  •     30 V output voltage rating
  •     Internal fixed-frequency PWM current control
  •     Satlington® sink drivers
  •     Brake mode
  •     User-selectable blanking window
  •     Internal ground-clamp and flyback diodes
  •     Internal thermal-shutdown circuitry
  •     Crossover-current protection and UVLO protection












3A Full-Bridge PWM DC Motor Driver Using A3959

Designed for pulse-width modulated (PWM) current control of dc motors, the A3959 is  capable of output currents to ±3 A and operating voltages to 50 V. Internal fixed off-time PWM current-control timing circuitry can be adjusted via control inputs to operate in slow, fast, and mixed current-decay modes. PHASE and ENABLE input terminals are provided for use in controlling the speed and direction of a dc motor with externally applied PWM-control signals. Internal synchronous rectification control circuitry is provided to reduce power dissipation during PWM operation. Internal circuit protection includes thermal shutdown with hysteresis, under voltage monitoring of supply and charge pump, and crossover-current protection. Special power-up sequencing is not required.

  • ±3 A, 50 V Output Rating
  • Low rDS(on) Outputs (270 milliohms, Typical)
  • Mixed, Fast, and Slow Current-Decay Modes
  • Synchronous Rectification for Low Power Dissipation
  • Internal UVLO and Thermal-Shutdown Circuitry
  • Crossover-Current Protection
  • Internal Oscillator for Digital PWM Timing










1.5A Full-Bridge PWM Motor Driver Using A4973 Circuit

The Schematic is based on A4973 IC, Designed for bidirectional pulse width modulated (PWM) current control of inductive loads, the A4973 is capable of continuous output currents to ±1.5 A and operating voltages to 50 V. Internal fixed off-time PWM current-control circuitry can be used to regulate the maximum load current to a desired value. The peak load current limit is set by the user’s selection of an input reference voltage and external sensing resistor. The fixed off-time pulse duration is set by a user- selected external RC timing network. Internal circuit protection includes thermal shutdown with hysteresis, transient-suppression diodes, and crossover current protection. Special power-up sequencing is not required. With the ENABLE input held low, the PHASE input controls load current polarity by selecting the appropriate source and sink driver pair. The MODE input determines whether the PWM current-control circuitry operates in a slow current-decay mode (only the selected source driver switching) or in a fast current-decay mode (selected source and sink switching). A user-selectable blanking window prevents false triggering of the PWM current-control circuitry. With the ENABLE input held high, all output drivers are disabled. A sleep mode is provided to reduce power consumption.

Note : – For Higher Motor Supply (12-50V) Input, Omit U2 , in the case logic 5V supply required and possible Motor supply range 12-50V DC 

Note : – Refer data sheet of IC A4973 for R1 and R2 Value

▪ ±1.5 A continuous output current

▪ 12 V DC Supply

▪ 3 V to 5.5 V logic supply voltage

▪ Internal PWM current control

▪ Fast and slow current-decay modes

▪ Sleep (low current consumption) mode

▪ Internal transient-suppression diodes

▪ Internal thermal shutdown circuitry

▪ Crossover current and UVLO protection




Inside IC A4973


3Amps DC Motor Speed & Direction Controller Using LMD18201 & 555 Timer

The circuit shown here are a DC Motor Speed and Direction Controller. Driver can handle DC Motor Load Up to 3Amp and DC supply 12V to 48V DC, The board is based on LMD18200 which is H-Bridge driver & 555 Timer IC generate PWM signal for speed control. Slide provided for direction Control. PWM duty cycle 10% 95%.

The LMD18201 is a 3A H-Bridge designed for motion control applications. The device is built using a multi- Shorted Load Protection technology process which combines bipolar and Internal Charge Pump with External Bootstrap CMOS control circuitry with DMOS power devices on Capability the same monolithic structure. The H-Bridge configuration is ideal for driving DC and stepper motors. The LMD18201 accommodates peak output currents up to 6A.

  • Motor Supply 12V 48V DC
  • Motor Load 3Amp 12V 48V DC
  • Logic Supply 5V DC
  • SW1 : Slide Switch To Change the Motor Direction CW/CCW
  • Duty Cycle 10% To 95%
  • Frequency 5Khz Approx.
  • Potentiometer Speed Adjust
  • LED Power Indicator

Note : J1 Jumper Close For Normal Operation.


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