meter

This is a little ideas of Easy In-line RF wattmeter circuit, it is insensitive to frequency, so calibration will be correct better than a wide frequency spectrum. For example the whole amateur HF spectrum; If the values of L2, the voltage divider at capacitors C1 and C2, and the resistances of R1 and R2 are [...]

The light meter is a tool, measure the quantity of light, widely used to a photography, To decide the correctness of the exposure. Sometimes, we are use with other works, such as my son likes to use in science experiments, which do not need to have high quality. This simple light meter in figure 1 [...]

This is audible light sensor circuit that is based the IC741 op-amp IC. This circuit light sensor one,these are use two LDRs for detector lower lightly. The 741 is pulse oscillator generator output to small speaker. The VR1 have value 50k acts as to fine sensitivity of light sensor. The speaker use small size only [...]