Circuits & Schematics - 3

In this Design Idea, we look at how electromechanical relays display hysteresis behavior that is surprisingly similar to the solid-state Schmitt trigger circuits, and how they can be used for many similar applications. This Design Idea is inspired ...

TinyCharger is an ATtiny25/45/85-based, single-cell Li-ion battery charger with selectable charging current limit (100 mA - 1000 mA) and an OLED display for monitoring. For Power Connecting device is equipped with a Micro-USB and a USB-C connector ...

A universal problem in battery-operated devices is the threat of damage when an end user (never an engineer) inserts the battery backward. You can avoid damage by inserting a single diode or by using a diode-bridge configuration, but those fixes ...

Care must be exercised when you try to “quickly” charge a nickel-cadmium (NiCd) cell or battery pack at a current density that approaches or exceeds one-third of its capacity (C/3). As the battery becomes fully charged, the high ...

This circuit increases the repeatability of noise test setups by providing reference points in the noise-vs.-frequency output generated by the network analyzer. It's based on Maxim MAX4475 , MAX427 , and MAX4101 op amps. Noise measurements can ...

Contactless washbasin taps that can dispense water without the risk of communicating diseases can play an important role in the battle against the COVID-19 virus. At present, most of the world’s washbasin taps are hand operated, but this ...

A key parameter of capacitors is their dielectric absorption (DA). If you want to estimate the capacitor’s quality or recognize its type of dielectric you can simply measure its DA. This simple circuit can help to avoid the time-consuming ...

Because the 8-pin ATtinys only have a few GPIO pins available, they are usually operated without an external clock. The internal oscillator does a good job in most applications, but when it comes to precise timing, its 10% accuracy is often ...

The simple circuit in Figure 1 uses a low-current-drain MAX4073H amplifier to sense the current flowing through a 4- to 20-mA loop. The circuit senses the current through a 1 Ω resistor with a fixed gain of 100 and uses no battery or dc power ...

The simple peak detector in Figure 1 is the result of a need for a single-5V-supply, level/clipping indicator for a multimedia-PC sound system. The design is unique in that it detects both stereo channels on a single peak-hold capacitor. All the ...