Mini DC Motor Speed and Direction Controller for Low Voltage Motors Using L293D & 555 Timer


Project has been designed around L293 H-Bridge for Bidirectional motor operations, & 555 Timer IC which has been used as PWM generator for speed control. L293 is capable of continuous output current 600mA. Operating voltage 5V DC. Specially designed for low voltage Mini motors. Great control on speed via onboard preset, while direction is controlled by changing jumpers settings. PWM Duty cycle range 20% to 90% . Great kit can be used in science projects, toys, mini motor speed controllers, robotics, model-making.

DC Motor Speed and direction controller project based on L293D H-Bridge and 555 Timer IC. 555 Generate PWM and L293D works as output driver. The 293D provides bidirectional drive current up to 600mA a voltage from 5V to 12V. L293D includes the output clamping diodes for protections.


  • Supply 5 to 12 V
  • Inhibit facility/enable
  • PWM Frequency 5KHz Maximum
  • High Noise immunity
  • Over temperature protection
  • Capable of delivering output current up to 600 mA per channel
  • The control/interface lines are accessible with Berg connector
  • Header connector for motor and supply connection
  • PR1 : Preset Speed Adjust
  • SW1 : 3Pin Jumper and Closer for Direction change
  • CN1 : DC Motor Supply input 5V to 12V DC





The L293 and L293D devices are quadruple high-current half-H drivers. The L293 is designed to provide bidirectional drive currents of up to 1 A at voltages from 4.5 V to 36 V. The L293D is designed to provide bidirectional drive currents of up to 600-mA at voltages from 4.5 V to 36 V. Both devices are designed to drive inductive loads such as relays, solenoids, DC and bipolar stepping motors, as well as other high-current/high-voltage loads in positive-supply applications.

Each output is a complete totem-pole drive circuit, with a Darlington transistor sink and a pseudo- Darlington source. Drivers are enabled in pairs, with drivers 1 and 2 enabled by 1,2EN and drivers 3 and 4 enabled by 3,4EN.