The Robot Power Simple-H is a low-cost robust H-bridge circuit suitable for use driving DC motors and
other DC loads in the ~25A and 6V-28V range. A wide range of command sources from switches
to 555 timer circuits to microcontrollers, BasicStamps and Arduinos may be used to control the Simple-H. The classic "green" Simple-H
requires 3V-5V logic level signals on its command inputs.
The Simple-H does not have any on-board logic to
interpret R/C, serial, analog voltage or other commands. An external signal source is required to translate
command inputs into the switching signals needed to drive the Simple-H power chips. This flexibility
allows the Simple-H to be driven from from a signal source as simple as a pushbutton or as complex
as a microcontroller or BasicStamp. Even a desktop or laptop PC can be used through a parallel port or
USB port expander.
New for 2011! The Simple-H HV is a version of the Simple-H that allows up to 28V input signals.
The circuit board footprint and mounting pattern is exactly the same between the two versions.
The indicator LEDs on the HV have a constant-current driver so their output is independent of signal voltage and
does not load the input signal. These features allow the Simple-H to be controlled by using switches directly off
the 12V or 24V battery voltage rather than requiring a 5V regulator to condition the input command voltages. Also 12V/24V
outputs from PLC modules may now be used directly to drive a Simple-H.
Unlike many competing products which advertise similar current ratings, the Simple-H ratings are for a period
measured in minutes or hours not a few seconds or less. One competitor even advertises a 30A controller where the
30A rating is for "a few milliseconds". With a Simple-H you can be sure if you need 20A of current you can
get 20A out of it for as long as you need it.
I wanted to inform you that our products passed (UL Certification) which also means the Simple H
passed. One test performed on the Simple H that may be of interest is
the cycling test. They performed 6000 on/off cycles at full current
at two second intervals (one second on for each channel)...
- Customer Ron P from PA, USA
I just wanted to let you know that I have used the Simple H-Bridge to overcome a problem with the auto-pilot control
unit on my 40' yacht. The Simrad autopilot installed on my boat drives an electrically powered hydraulic control
ram. The motor can draw over 15 amps when fully loaded but has an average current of <3 amps. The J3000X control
unit installed was rated for 6 amps continuous and 10 amps for 5 seconds, which was clearly under-rated for the
application and would regularly drop out. Simrad make a higher power control unit (J300X) with 10 amps continuous
and 20 amps for 5 seconds, but it is very expensive as it contains all the smarts of the autopilot, which I
already have in the J3000X unit. So I used one of your Simple H-Bridges, interfaced appropriately to the
J3000X and it works brilliantly. Naturally I carry a spare! Thanks for developing a great little product.
- Customer Chris D. from Sydney, Australia
The Simple-H has the following specifications and features:
||5V to 28V (24V max battery rating)|
|Output Current (continuous)
||20A (25A with fan)|
|Output Current (surge)
||2 ea. BTS7960B|
||.016 ohm max at 25C|
||DC to 20kHz|
||Heatsinks and optional 20 CFM 50mm fan|
||3V - 5V classic version|
4V-28V HV version
min. 2 digital signals required to drive
|Current and Temp Limiting
||Built in to power chips|
|Current Sense Outputs
||0.0745V per Amp - 2.98V at 40A|
||8-pos 0.1" screw terminal, 2-pos fan terminal|
4 each screw terminals for power wires
A User Manual and Schematic diagram are available for more detailed information.
Six command/status connections are provided via an 8-position screw
terminal on the Simple-H. The hole spacing allows a standard 0.1" pin header to be substituted
for the screw terminal if desired. Jumpers allow the user to configure the Simple-H as a single
full H-bridge or two independent 1/2 bridge circuits. The 1/2 bridge circuits may be ganged
together for increased current handling.
|CN1 - Command/Status Connector Pinout|
||PWM A - A-side 1/2 bridge control input|
||PWM B - B-side 1/2 bridge control input|
||Enable A - A or A&B-side* enable|
||Current A - A or A&B-side** current sense output|
||Enable B - B-side enable|
||Current B - B-side current sense output|
|* with EA jumper installed in J1|
** with CA jumper installed in J1
Click for larger image
The Simple-H uses heatsinks and heavy copper areas on the circuit board to dissipate heat. This
results in a current rating higher than for most motor drives of similar size. To get the maximum
possible current or to run for exetended periods close to maximum the Simple-H uses an optional
cooling fan to further dissipate heat. The fan itself is
a commonly available 12V 50mm square computer cooling fan. Mounting holes are provided at the
correct spacing to mount the fan directly over the power chips for maximum cooling efficiency.
Robot Power offers the Simple-H in fully assembled units.
Check the Web store for details on prices and