Circuits & Schematics - Supply - 9

Variable regulated power supplies are handy tools found on well-equipped electronics lab benches. The symmetrical varieties that produce equal voltage outputs of opposite polarity, are even more so. Figure 1’s version of a symmetrical 0 V to ...

This is one real-life quest: How do we increase the output voltage of a step-up converter? If you have unlimited access to the right ICs, you are one lucky dog, but what if you don’t? Or maybe you are limited to a specific chip due to ...

A two-terminal current source using the basic circuit of Figure 1a can be enhanced by adding on an independent subcircuit that uses degeneration of a PNP transistor to achieve zero temperature coefficient (tempco or TC). This low-cost design is the ...

A common technique for implementing PWM involves comparing a triangular waveform of fixed amplitude and frequency with a variable dc voltage level. Although this approach results in a PWM signal of precise frequency and with duty cycle variable ...

There are many circuits of soldering station controllers, but absolutely all close the temperature feedback loop using the soldering iron heater thermistor. The performances of the soldering station can be improved and the circuit can be made ...

Using the system shown in Fig. 1, you can quickly test a cable containing twisted-wire pairs and detect open or reversed pairs, shorted pairs, and shorts between unrelated pairs. The tester consists of an active test set that plugs into one end of ...

Let’s imagine that you need to add a power switch to something that’s battery-powered but processor-free; perhaps it must also be waterproof and thus membrane-sealed. Or perhaps you just want to use a shiny modern push-button rather ...

A high-side current-sense amplifier, IC 1 , offers a simple method of combining low-speed clocks or other signals with dc power in cables between subsystems (Figure 1). Designed for monitoring charge and discharge current in secondary batteries, IC ...

Latching relays change their states when you apply a short voltage pulse to their coils. Because these relays require no continuous coil currents to keep their states, you can save considerable power in the driver circuit. In one type of latching ...

In recent EDN design ideas, we’ve seen thermostat designs that meld the functions of sensor and heater into a single device: FET, BJT, or even a simple length of fine gauge copper wire. A virtue inherent in thermostat designs that use a ...