Despite having access to an oscilloscope, [Brian] aka [schoolie] has come up with his own method for measuring PWM period and duty cycle without a scope, just in case there’s ever a PWM emergency!

(See Fig. 1.) Microcontrollers and DSPs often incorporate such PWM conversion circuits as on-chip peripherals to drive electromechanical components like brakes and motors.

Because it uses only six components, this circuit can be very cost effective. The LM431 can be purchased for as low as 10 cents in single-unit quantities, well below that of any op amp. Editor’s ...

Today, three decades later, digital PWM controllers include such obvious analog blocks as A/D converters, references and even amplifiers. Clearly, the right answer depends on a suitable partitioning ...

The most common type of power supply today is the switching supply. These units use pulse-width modulation (PWM) to regulate output. Supplies today employ several different PWM circuit configurations.

Figure 2. Typical Feedback Circuit with Optocoupler Primary/Secondary Isolation Components R1, R2, C1, R3, C2, R4 and R5 were chosen during the loop analysis stage of the design to satisfy the control ...

Looking at the circuit diagram, the "+12V" and "0V" terminals connect to the respective connections on the PSU Molex connector. The "FAN+" and "FAN-" connect to the corresponding +v and -v ...

So problem solved right? Well, sort of. It really bugs me that there’s an entire arduino there just for some PWM. I can go buy the components to do 555 timer PWM circuits if all I want is PWM.

In a basic implementation of the power-monitor circuit (Fig. 1), current passes from source to load through the current-sense resistor R1. In conjunction with R1, U1 provides an output voltage ...