Free Circuit Diagram

A simple half-wave peak detector using a single transistor is very compact and low cost, but if the application require precise detection for signal under 100mV then that circuit become useless. Here you can use more precise half-wave detector using only a single op-amp woth few passive components. Look at the circuit’s schematic diagram below.

The [...]

Using only a single transistor and few passive components, you can build a fairly sensitive peak detector. This peak detektor is suitable for audio application, since the average sum of positive and negative cycle of audio signal has equal value. You can find a tpeak signal although you only detect the peak of positive cycle. [...]

This charger circuit is suitable for lead-acid battery, including flooded, gel, and AGM types. The automatic term means that this charger will stop charging automatically when the battery voltage reach a certain pint, indicating that the battery has been fully charged, and charging will be restarted if the battery voltage falls below that threshold. A [...]

This audio frequency meter uses 555 IC as a monostable multivibrator (one-shoot trigger). A monostable multivibrator can act as a frequency-to-voltage converter because it produce a fixed pulse width, with the repetition rate/density is proportional to the triggering input frequency. Here is the circuit’s schematic diagram:

For resistor R1, because it set the measurement range, it’s [...]