Diverse Electronic Services

MC-7


A motor controller with a WIDE operating voltage (12 to 36 volts) and 35 amp capability
that can be controlled manually or directly from the microprocessor or PC of your choice.

MC7 Motor Controller Specifications

• Model MC7: ONE controller for 12 volt to 36 volt applications. No need to make a choice now then have to purchase a new controller if your system changes.
   
• 35 amps continuous (Fan cooling required when operating at 36 volts)
   
• PWM output, continuously variable speed from stop to full forward or reverse.
   
• Compact circuit board approx. 3.75" X 5.75" w/ 4 mounting holes.
   
• Utilizes 3 IRFZ48 power hexfets for motor control with massive individual heatsinks
   
• PCB traces are 2 oz. copper instead of the standard 1 oz copper found on most other PCB's.
  Control it manually with only 2 components needed- a standard 5K linear taper potentiometer for speed and a SPDT toggle w/ center off for direction control.
   
• Control it from your microprocessor by applying a PWM control signal between the "pot wiper" (PW) terminal and ground to control speed, and a +5V signal on either the forward or reverse connectors to control direction. Enable it with +5V on the enable terminal.
   
• No standby current drain. Leave power connected to the B+ and ground terminals permanently. No current is drawn until +5V is applied to the enable lead.
   
• Ramped forward and reverse speed acceleration. This means that if you suddenly apply a full forward or reverse control signal your robot, or other project, it will not attempt to do a "wheely" or otherwise start suddenly. The acceleration, forward or reverse will always be smooth, yet still rapid. This feature may be disabled for instant control.
   
• .250 terminals used for all connections. No special plugs or cables needed. Universally connect to any outside circuitry.
   
• Controllable by a DC control voltage (1 to 3 volts) or by a BS1, BS2, PIC or other micro via the PWMOUT command or from the parallel port of a PC without any additional hardware.
   
• On-board EMI suppression eliminates interference from most noisy motors. FREE components provided, if needed, for extra noisy motors to suppress stubborn EMI emissions.
  
  PLEASE NOTE: This motor controller is meant for hobby robots or small to medium professional robots and light industrial applications. It is NOT meant to be used with electric scooters or wheelchairs because it has not undergone expensive FCC & FDA testing for
  EMI (radiated & susceptibility) and ESD required for use in these services. The MC7 is NOT WARRANTED as a fail safe device. As such, it should not be used in life support systems or in other devices where it's failure or possible erratic operation could cause bodily injury or loss of life.
  
  PRICE: only $95 each. Compare that to any other 35 amp controller on the net!
  (If you can find one with this wide operating voltage)

To see spec sheets and connection diagrams on the MC7 in .pdf format, click HERE

Protect your controller!

As shown in the connection diagrams, some means of current limiting is STRONGLY recommended. This is usually a fuse or a circuit breaker inserted in the B+ lead of each MC7 to protect it from overload currents. A current rating of about 25% over the normal operating current is recommended for fuses.

A fuse is, initially, the least expensive way to do this, but you have to replace it every time you exceed it's ratings and it will blow on temporary peak overload currents.

A correctly designed circuit breaker will allow peak currents for short amounts of time without blowing and will open on sustained overload currents.

If you expect to be utilizing the full 35 amp capability of the MC7, the circuit breaker shown below can be good insurance. It was designed specifically for this controller. It will allow 35 amps continuously and 60 amps for about 20 seconds before it opens the circuit. This is within the ratings of the MC7. A plus feature is that it will automatically reset after about 20 seconds so no manual resetting or replacement is required.

To see spec sheet on circuit breaker in .pdf format, click HERE

Please Note:

If your motors will be drawing considerably less than the rated 35 amps, even at stall, you probably won't need these circuit breakers. A fuse rated at about 25% above your stall current will suffice.

Also, circuit breakers or fuses will NOT protect the MC7 (or any motor controller) from catastrophic failures such as shorted wires or motor windings or motors with excess stall currents. They are useful only on relatively gradual current increases over the normal limit such as experienced during hill climbing or pushing against another object.

These circuit breakers are in stock and are only $5.00 each. Shipping for the breakers is free when ordered with the MC7.

This board is completely repairable, in most cases, for a flat fee of $40.00 including parts and labor. S&H is extra. Typically $5.00 for 1 card. Turn-around time (from the time received to the time it is mailed back) is, usually, 2 weeks or less. I reserve the right to return the board if it is unable to be repaired. This may be due to traces that have been damaged extensively through some major mishap. Call 570-735-5053 to obtain a Return Authorization number, which  MUST be on any package containing a controller for repair.

MC7 Price is $95.00

PA residents add 6% sales tax

Pinout Table

Analog Control Connection Diagram
Digital Control Connection Diagram
Digital Control Connection Diagram for BS2
Digital Control Connection Diagram for PIC16F84

To see spec sheets and connection diagrams on the MC7 in .pdf format, click HERE

Sample programs- BS2 control of an MC7 controller (in Stamp2 basic)
Sample programs- PIC16F84 control of an MC7 controller
(in PicBasic, hex, assembler & machine language)