Circuits & Schematics - 2

At the end of the DI for a Simple log-scale audio meter (Ref. 1), I promised to show how to upgrade it to work better. With these fixes, it now has near-digital performance, with faster response and smoother operation. Even this supersized version ...

As the latest generation of new LEDs achieves higher levels of power and efficiency, use of these devices extends to new areas, such as flashlights and vehicular applications. High-power LEDs are finding use even in ambient lighting, long the sole ...

I recently purchased a new oscilloscope for home use. It’s a 250 MHz scope, but I was curious what the actual 3 dB frequency was as most scopes have a bit more upper end margin than their published rating. The signal generators I have either ...

When a design needs auxiliary voltage rails and the associated current loads are modest, capacitor pump voltage multipliers are often the simplest, cheapest, and most efficient way to make them. The simplest of these is the diode pump voltage ...

When analog circuits mix with digital, the former are sometimes dissatisfied with the latter’s usual single supply rail. This creates a need for additional, often negative polarity, voltage sources that are commonly provided by capacitive ...

The logic probe is powered from the device under test (DUT) it may be any binary logic, which can be powered in the range +2 V to +6 V. This may be a microcontroller or 74/54 series logic chips, including HC/HCT chips. The probe determines 3 ...

Differential temperature measurement is a handy way to quantify the performance of heatsinks, thermoelectric coolers (TECs), and thermal control in electronic assemblies. Figure 1 illustrates an inexpensive design for a high-resolution differential ...

Conventional thermostats are based on separate temperature sensor and heater devices with means for feedback between them. But in some recent EDN design ideas (DIs) we’ve seen thermostat designs that meld the functions of sensor and heater ...

The circuit in Figure 1 shows an electronic switch driven by a momentary pushbutton, which turns the power alternately on and off. It was designed for battery-powered equipment. The easiest way to implement it is to use a flip-flop IC, such as the ...