Circuits & Schematics - Measurement - 5

Frequent contributor Nick Cornford recently published a delightfully clever design idea ( Reference 1 ) using a platinum RTD calibrated to output a 1 mV/ C signal that’s perfect for direct readout via a standard DMM I thought Nick’s ...

Way back in 1986, famed analog innovator Jim Williams, in “Designs for High Performance Voltage-to-Frequency Converters” ( Reference 1 ) published his “King Kong” 100 MHz VFC. I have never seen its equal. Certainly Figure ...

Before shipping moving-coil meters, manufacturers may short-circuit the meters' terminals with a length of wire, which provides effective electromagnetic damping and results in better immunity to external mechanical vibration and shocks that ...

Psychologists tell us that frustration increases drive. I was driven to produce the circuit in this design idea by my increasing frustration with a collection of digital thermometers, all of which claimed accuracy to within 0.1 C but the readings ...

An excerpt from Christopher Paul’s “Parsing PWM (DAC) performance: Part 1 Mitigating errors” ( Ref. 1 ): “I was surprised to discover that when an output of a popular µP I’ve been using is configured to be a ...

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 ...

Let’s see how you can effectively double the output sink current of the plain old 555 timer. From the block diagram in Figure 1 taken from the datasheet of the ST’s TS555 low power single CMOS timer) we can see that the Discharge pin ...

You can use the simple sensor circuit in Figure 1 to remotely monitor the level of liquid water in a vessel such as a swimming pool. The LMC555 sensor oscillator provides an output-signal frequency that is a function of the water level. This signal ...

Pulse width modulation (PWM) is a terrific basis for digital to analog conversion. Credit goes to features like simplicity and (theoretically) perfect differential and integral linearity. Unfortunately, PWM’s need for ripple filtering tends ...

Battery stack voltage monitor development ( Reference 1 ) is aided by a floating, variable potential battery simulator. This capability permits monitor accuracy verification over a wide range of battery voltage. The floating battery simulator is ...