Archive for the ‘Control and Monitoring’ Category
Battery Level Indicator
A battery level indicator circuit is depicted in the schematic diagram below. This circuit is designed for 9V battery operation, as this circuit will start dimming below 7V and will be completely turned off at 6V. If you want the LED indicator not to dimming but just abruptly turns off at below 6V, then you …[Read More]
Logarithmic Light Intensity Meter for Photography
Using LM10 amplifier and voltage reference, a light intensity meter featured with five decades dynamic range (which is suitable for photographic application) can be built. Please note that the linear to log conversion is not temperature compensated, and can make 40% error (a half stop in photography) at the worst point of conversion slope at …[Read More]
National LM378 amplifier is used as a basis for economical proportional motor speed controller. This integrated circuit is able to deliver 700 mA continuous current for such DC motor applications such as antenna rotors or motor controlled valves. The basic of proportional control is as simple as amplifying the error signal to produce an action …[Read More]
Chromel Alumel Thermocouple Current Loop Transmitter
The schematic diagram below show signal conditioning circuit for remote current loop temperature transmitter. This thermocouple temperature transmitter is loop powered, means it doesn’t need its own power supply since the supply is provided by the current loop receiver. Thermocouple is basically a junction of two different metallic material that measures the temperature difference. This …[Read More]
Power Amplifier’s Overload/Clipping Indicator
Clipping is a condition where a signal is truncated by insufficient processing. The cause of clipping can be different for various case, but most of them, especially in power amplifier stage, is because the amplifier is forced to serve out-range of power when the input volume is too high. Detecting severely clipped signal is easy …[Read More]
Audio-Controlled Incandescent Lamp Light Controller
This is a audio-controlled lamp circuit. This circuit requires low voltage input such as pre-amplifiers, tone control, or general audio line level output. It’s also possible to feed the input with signal from small power amplifier output, or high power amplifier witk low volume level. The characteristic of lamp dimming (incandescent lamp) will look like …[Read More]
Current Loop Light Level Detector
This circuit is two wire light level detector, we don’t separate wires for power this sensor system and for delivering the output signal. With current loop, we do both function in a single pair of cable, just provide the voltage supply and measure the current as the output signal. The core of this circuit is …[Read More]
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