Random circuits

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Sleeping-Aid

Many people experienced sleeping well in natural surroundings, into a tent or a wooden hut. This fact is due not only to the healthy atmosphere but also from our unconscious ability to perceive natural Earth's magnetic-fields. The circuit generates this type of Geo-magnetic-fields and lets us perceive them: in this manner our brain is surrounded by an ideal environment for a sound sleep.... [read more]

Headphone amplifier with TDA2004

A opamp. medium power, here it‘s used as amplifier of headphones with possibility drive low loads. It contains in a nutshell two amplifiers.... [read more]

10 Band Graphic Equalizer

The circuit of graphic equalizer, allocates ten adjusting potesometer , that each one from them affects in a predetermined area of frequencies, the central frequency of which abstains a octave (double), from the central frequencies of her neighbouring regions. Each unit has common materials with remainder and it differs only in the capacity of capacitors that constitutes the filter in each unit.... [read more]

AM To FM converter

AM To FM converter... [read more]

Doorbell Memory Circuit Diagram

If you’re expecting an important visitor but you just have to step out for a moment, an electronic doorbell memory can come in handy so you can see whether someone rang while you were out. Of course, you can’t tell whether it was the visitor you were expecting who dropped by then, but a call to the mobile phone of the person concerned can quickly answer that question. A doorbell memory can also save you the trouble of going to the front door (if you live upstairs) when you think you heard the bell but aren’t sure. And if you can’t buy one, then of course you can build one yourself! Read on to find out how.... [read more]

Fixed Voltage Power Supply

The fixed voltage power supply is useful in applications where an adjustable output is not required. This supply is simple, but very flexable as the voltage it outputs is dependant only on the regulator and transformer you choose.... [read more]