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Pulse Modulator Comparison

Power Pulse Modulators

Here you can compare the various attributes of our pulse width modulation circuits so that you can see which model will most suit your needs.

Model Variations

There are two main models of PWM available, these are the PWM-OCm and the PWM-OCX(v2). The OCm represents a miniature basic model, while the OCX v2 is an advanced model with many extra features and more power. There are currently two versions of each model. Ones with an “i” suffix (e.g. PWM-OCXi) are high voltage versions which use IGBT transistor technology, while ones without the suffix are low voltage MOSFET versions.

The two types of transistor technologies offer their own advantages and disadvantages. IGBT’s will tolerate much higher voltages and are therefore great for use with coils or transformers. MOSFET’s can pass higher currents and can be more efficient, this advantage comes at a tradeoff with the voltage tolerance and these are therefore best for non inductive loads such as lights or electrolysers.

75V, 8A, 100kHz
300V, 3.5A, 100kHz
pwm-ocx-v2PWM-OCX v2.1
50V 24A 1.5MHz
Advanced protection
Advanced features
pwm-ocxi-v2PWM-OCXi v2.1
500V 9A 1.5MHz
Advanced protection
Advanced features


Current vs Frequency

The graph below shows max average current that you should allow to flow at a given frequency. You can clearly see the superior power and frequency performance of the OCX v2 and OCXi v2 models.


These values were obtained under the test conditions outlined in the product manuals. You should use this only as a guide as different conditions will alter the heat generated in the components.

The current ratings given are for when one or more components has reached around 100C and is no-longer increasing in temperature. When cold, it is ok to pass more current than shown in the graph, but only for a short time as the components will soon heat up.

PWM Features

  OCm OCmi OCX v2.1 OCXi v2.1
Max Current 8A 3.5A 24A 9A
Max Voltage 75V 300V 50V 500V
Max Frequency 100kHz 100kHz 1.5MHz 1.5MHz
Passive Transient Voltage Protection YES YES YES YES
Active Transient Voltage Protection NO NO YES YES
Over Voltage and Over Current Indicator NO NO YES YES
Adjustable Over Current Protection NO NO YES YES
Monostable Pulse Mode NO NO YES YES
Invertable Output NO NO YES YES

Custom Versions

PWM-OCBILWe can customise our circuits to meet your requirements if possible. Typical customisations might be to use a specific transistor of your choice, or to integrate it with some control hardware in an enclosure.

If you would like a unit customised, please use this custom PWM form.

Further Reading

We have a range of pages with photo’s and video of our PWM units in action. On these pages you can learn more about using them, and also what kinds of things they can be used for. Check the Product Guides page for more info

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