Signal Consulting, LLC 

Model Si20HPB4-50V-20A-AP1

50V-20A High Power H-Bridge with Aluminum Plate Heat Sink for Bidirectional DC Motor Control





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Si20HPB4-50V-20A-AP1 Features:

Max. Continuous Load Current: 20A with board mounted on a large metal frame.
Max. Load Current for 2 sec: 50A with board mounted on a large metal frame.

Overall Dimensions:  4.0"x 3.3”x1.4”, (102 x 83 x 36 mm).

Board Isolation:    The PWM Control Lines are Optically Isolated from the Motor-Power Circuits.

Typical Operating Temperature:  450C at 16A with the board mounted on a 4.0” x3.3” x0.062" Aluminum plate and exposed to air at 250C. Please click on this link and read the Board Mounting Instructions and Heat Sink Selection Guide.

Voltage Requirements: A Single DC Source (unregulated and unfiltered). Any voltage from 9V to 50 Volts ( from Pin +P to Pin -P).

Control Type: Active High, (0 to 5V)
Typical Power Efficiency: 98.5% at full-load (50V and 20A).

Load Isolation: The Load Must be Isolated for the Power Source.
Components Type: 100% Solid State, NO Relays

On Board: 
Filter Capacitors.
VTS diodes.
Snubber Circuit.


    For Details, Download the  Si20HPB4-50V-20A-AP1-8   Manual


The Si20HPB4-50V-20A-AP1 is an efficient high-power H-bridge with an integrated (4"x3.3"x0.062") Aluminum Plate Heat Sink  that works over a wide range of source voltages (9V to 50V) at high continuous load currents (+/-20A max).  Higher current values can be attained with more efficient heat sinks. The motor action (as shown on the truth table below) is controlled by the voltages applied to pin F and pin R (relative to pin C) on the Control connector (shown on the application drawing below). These pins are optically isolated from the rest of the power circuit, requiring a minimum input current of 1.5 mA at 3.5V and max input current of 7mA at approx. 9V. An external resistor, (connected in series with each control input F and R) can be used when higher control voltages are required (1kW for 12V, 2.2kW for 24V).

 Control Input Truth Table (for Control connector)



Motor / Load  Action

LOW = 0 Volts

LOW = 0 Volts

Motor Stop / Load Current OFF

HIGH = 5 Volts

LOW = 0 Volts

Motor Forward / + Load Current

LOW = 0 Volts

HIGH = 5 Volts

Motor Reverse / - Load Current

HIGH = 5 Volts

HIGH = 5 Volts

NOT Recommended*

* When VFC and VRC are HIGH at the same time, the motor will spin forward or reverse depending which control signal arrives first; but no damage will occur to the load, board or the power source.

         The VFC and VRC control lines can be Pulse-Width Modulated (PWM in a range of 0-20k HZ) to vary the average current supplied to a load or to a DC Motor.

           A bicolor LED is used to monitor the load voltage (Forward = Red, Reverse = Green).

Voltage Requirement: The Si20HPB4 will work with any DC motor in the 9 V to 50 V range. In addition, the power filters are included on this board. Consequently, only unregulated DC input power is required in most applications. Furthermore, the control circuit is optically isolated from the power circuit; rejecting unwanted power glitches.    

Frequency Response of the Si20HPB4-50V-20A-AP1

The Si20HPB4 control inputs (VFC, VRC) can be Pulse Width Modulated (PWM with duty-cycle of 0% to 100%) over a wide range of carrier frequencies, as shown on the graph. This plot was obtained with the board mounted on a 4.0” x 3.3” x 0.062” Aluminum Plate, placed on a nonmetallic bench top and exposed to 25 degree C air. Improved performance (20A) can be achieved with the board mounted on a metal frame (- - With Extra Heat Sink). Please click on this link and read the Board Mounting Instructions and Heat Sink Selection Guide.  

 A Typical Motor Control Application of the Si20HPB4-50V-20A-AP1

 In this bidirectional speed control application, the motor speed and direction is controlled by 2 external signals connected to pin F (Forward) and to pin R (Reverse) on the Control connector. These two (0 to +5V , relative pin C) inputs can be Pulse –Width Modulated over a wide Frequency range. These three pins are optically isolated from the power supply and the load.

Warning:  The connecting wires to the Load and the Power Supply must be heavy gauge copper wire (#12 AWG or heavier) to handle the rated current level. In addition, these heavy gauge wires act as a heat sink, protecting the board from overheating.

 Typical Applications: Power Driver for Variable-Speed Bidirectional DC Motors, Peltier Effect TE Cells, Heat Pumps, PPDT Solid State Relays.

Si20HPB4-50V-20A-AP1, 50V 20A H-Bridge with Aluminum Plate Heat Sink
Price  $119.00

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Availability: We usually ship in 2-3 business days.



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