How do I choose a microcontroller or single-board computer for a robotics prototype?

Match the controller to your project's compute needs, I/O count, and communication interfaces (GPIO, PWM, UART, SPI, I2C, CAN). Consider power budget, real?time requirements, available development libraries and community examples (e.g., Arduino, Raspberry Pi families), and confirm part availability and datasheets on the product page before ordering.

What should I check when selecting motors and motor drivers for robots?

Select motors based on required torque, speed, voltage and continuous vs stall current, and pair them with drivers rated for the motor's peak current and control method (brushed, brushless, stepper). Review datasheets for torque curves and cooling needs, and account for gearing, feedback sensors and the controller interface when planning your drivetrain.

Can I collect orders from a Communica branch and obtain a VAT invoice for institution purchases?

Yes — branch collection is available from the Samrand head office and branches in Pretoria (CBD) and Cape Town; choose the branch pickup option at checkout and present your order reference and ID on collection. VAT invoices can be issued for business or educational purchases; request invoice details at checkout or via the sales channel used for your order.

What are typical lead times for out?of?stock components and how do backorders work?

Many items are stocked locally, but specialist components may have supplier lead times; the product page normally shows current stock status and any estimated ETAs. For procurement or bulk needs you can request a quote or backorder option to confirm delivery timelines and minimum quantities.

Does Communica support educational or classroom robotics kits and bulk procurement for tertiary institutions?

Communica offers component kits, development boards, 3D printing supplies and test equipment suitable for classrooms and labs, and can provide bulk quotations and VAT invoicing for institutions. Check the education requirements when requesting a quote to ensure kit content, quantities and delivery or branch pickup options meet your curriculum needs.

What types of robotics and prototyping components does Communica stock?

Communica stocks microcontrollers and development boards, sensors, motors and drivers, power supplies, connectors and enclosures, 3D printing consumables, tools, and test & measurement equipment from a wide range of global and maker brands. Product availability can be checked on the online catalogue or by contacting your local branch.

How can I check stock availability and estimated lead times for parts?

Check the product page on communica.co.za for current stock indications and lead-time notes, and contact the Samrand head office or your nearest branch for confirmation on backorders or import lead times. For larger or time-sensitive orders, request a formal quote or lead-time confirmation from sales so you have a documented delivery estimate.

Can I collect my order from a Communica branch or do you only ship?

You can choose branch collection (Samrand, Pretoria CBD, Cape Town) or courier delivery at checkout; branch trading hours and collection details are listed on the Branches & Trading Hours page. For branch collection request a VAT invoice or packing slip at pickup.

Do you support educational and bulk procurement for robotics courses or labs?

Yes — Communica supplies schools, universities and industry with component kits and larger quantities; departments should contact the sales team with a parts list and delivery requirements to obtain volume quotes, lead times, and VAT-compliant paperwork. Early engagement helps manage stock allocation and import lead times for semester planning.

How do I choose the right motor and driver for a mobile robot prototype?

Match motor voltage and continuous/peak current ratings to the driver specification and battery system, and select torque and RPM based on robot weight, wheel diameter, and required acceleration; include a safety margin for stall current and thermal dissipation. Review datasheets, estimate your power budget, and confirm component availability or compatible alternatives with Communica before finalising the design.

Troubleshooting Common Issues with PWM DC Motor Controllers (South Africa)

Learn practical troubleshooting steps for PWM DC motor controllers: diagnostics, wiring diagrams, PWM checks, thermal fixes, and local parts sourcing in South Africa.

Published:December 10, 2025

7 min read

Image supplied by 123RF

Start with Power

Measure supply voltage and wiring under load before anything else.

Inspect PWM Signals

Use a scope to check frequency, duty cycle, and ringing at outputs.

Suppress Transients

Add decoupling capacitors, snubbers, or TVS diodes to reduce failures.

Overview: Why PWM DC Motor Controllers Fail and How to Start

Pulse-width modulation (PWM) is the most common method to control DC motor speed and torque in robotics, automation, and maker projects. This guide on troubleshooting common issues with PWM DC motor controllers focuses on symptoms you’ll see, simple checks you can perform with basic tools, and quick fixes that work in South African labs and workshops. Start by isolating mechanical, electrical, and firmware causes - then progress to measurements and component swaps.

Initial checklist

Confirm correct supply voltage and polarity
Inspect wiring: connectors, crimps, and solder joints
Check motor condition (bearing noise, stalls)
Verify controller config: PWM frequency, dead-time, and logic levels
Have a digital multimeter (DMM) and oscilloscope handy for signal-level checks

Common symptoms and quick diagnostics

Use the symptom to pick tests: if the motor hums but won’t spin, suspect low supply, wiring, or heavy mechanical load. If it jitters or vibrates, check PWM frequency and grounding. If the controller overheats, look at current draw, ventilation, and duty cycle. Record the exact behaviour before changing anything - a short video helps reproduce intermittent faults when consulting datasheets or specifications.

Standards, specs and key parameters to check

When troubleshooting common issues with PWM DC motor controllers, pay attention to these specifications on the controller and motor datasheets: supply voltage range, continuous and peak current ratings, recommended PWM frequency, logic input voltage (TTL/CMOS), and thermal derating. In South African projects it’s common to use 12V, 24V or 48V systems - always match the controller’s rated voltage and confirm that fuses or supply cables are sized appropriately in ZAR-spec installations. For more background, see our buying guide for DC motor speed controllers.

Parameter	Why it matters	Quick check
Supply voltage	Over/under-voltage affects torque and controller operation	Measure with DMM at controller V+ and GND under load
Continuous/peak current	Exceeding ratings causes thermal shutdown or MOSFET failure	Estimate using motor stall current; compare to controller rating
PWM frequency	Too low causes audible noise; too high increases switching losses	Use scope to view the PWM waveform at the controller output

Tools and local procurement notes

Digital multimeter and clamp meter for current checks
Oscilloscope to inspect PWM waveform and ringing (available in test benches)
Decoupling capacitors, flyback diodes, and ferrite beads for noise suppression
Replacement MOSFETs or driver modules; Communica stocks semiconductors and test equipment - browse 30a-pwm-dc-motor-speed-controller-for-6-60v-applications for parts
For branch pickup or to check local stock, see applications-of-30a-pwm-dc-motor-controllers-in-industry

Fault: Motor does not respond (no spin)

If the motor is inert, follow these steps in order to narrow the cause.

Step-by-step checks

Confirm the controller has power: measure V+ to GND at the controller terminals.
Verify control input: measure PWM input pin with DMM (DC value) or scope (signal present).
Check enable or fault pins: many controllers require an enable high/low - consult the datasheet.
Temporarily disconnect motor and measure controller output voltage; if outputs show expected PWM but motor still won’t spin, suspect motor or wiring.
Swap with a known-good motor or controller where possible to isolate the failing assembly.

Wiring ASCII diagram (basic)

  Power Supply (+V) ----+---- Fuse ----+---- Controller V+
                         |                      |
                         +---- Motor + ---------+---- Controller OUT+
  Power Supply (GND) ----+----------------------+---- Controller GND

  PWM Signal (microcontroller) ----> Controller PWM_IN
  NOTE: Add flyback diode or ensure controller has internal protection.

In many SA workshops, poor crimps or thin supply leads cause voltage drop under load - measure at the controller, not at the battery or PSU terminal, to spot this. For a practical guide on setting up your controller, refer to how to use a 30A PWM DC motor speed controller.

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