If you have a load with a variable or poorly specified resistance and want to regulate the power applied to it (a heater for example), merely controlling the voltage or current will not work, as in both cases the power P = I 2 R = V 2 /R depends on ...
Figure 1 gives a simple circuit for the PUSH ON, PUSH OFF function with only a few inexpensive components. In this design, the output is connected to the input of the gadget when you press the push button (PB) once. For the next push, the output is ...
The LM4041 has been around for over 20 years. During those decades, while primarily marketed as a precision adjustable shunt regulator, this classic device also found its way into alternative applications. These include voltage comparators, ...
Almost every wall power supply has no indicator showing whether current is consumed by the load or not. It seems that this was a shortcoming that was not only noticed by me: I once saw the solution given in Figure 1. Figure 1. Wall power supply ...
Switching power supplies can be notorious noise generators. You should prevent this noise, which is conducted, radiated, or both, from returning to the input source, where it can potentially wreak havoc on other devices operating from the same ...
Figure 1’s negative constant current source has been a textbook application for the LM337 regulator forever (or thereabouts). It precisely maintains a constant output current (I OUT ) by forcing the OUTPUT pin to be the negative V ADJ ...
LM317 fans will recognize Figure 1 as the traditional LM317 constant current source topology. It closely regulates I OUT = V ADJ /R S by forcing the OUTPUT pin to be V ADJ = 1.25 V positive relative to the ADJ pin. Thus, I OUT = V ADJ /R S to a ...
The circuit of Figure 1 is designed for portable-power applications that require white LEDs with adjustable, logarithmic dimming levels. The circuit drives as many as four white LEDs from a 3.3 V source and adjusts the total LED current from 1 to ...
When designing devices with microcontrollers (MCU), I like to use some of the analog-to-digital converter (ADC) inputs to measure onboard voltages along with all the required sensors inputs. This means I often run out of ADC inputs. So presented ...
There’s been a lot of interesting conversation and DI teamwork lately devising circuits for ON/OFF power control using inexpensive momentary-contact switches (See Ref. 1 Ref. 4 ). Most of these designs have incorporated edge triggered ...