Mutchus

Build a Simple Solar Powered Long Range FM Transmitter Circuit Diagram . This is very stable, harmonic free, long range fm transmitter circuit which can be used for fm frequencies this one is unique in that it runs completely on solar power. No battery is required. As long as the sun is shining on the PV panel, the transmitter will transmit. The transmitter bug is useful as a "remote ear", and can be used for anything from listening birds to surveillance work. The mic preamp and oscillator circuits were borrowed from a common circuit found around the Internet, a regulated solar power supply and an RF amp that extends the range of transmitter and improves frequency stability were added.    Simple Solar Powered Long Range FM Transmitter Circuit Diagram Theory The solar power supply consists of a small 18V PV panel which charges a 1000uF electrolytic capacitor. The capacitor keeps the circuit running during brief interruptions of light, such as a bird flying over the PV panel. T...

Simple mechanical timers, which you can buy for a couple of pounds in every home improvement centre, are suitable for switching something on and off one or more times per day. They can be used to control a wide variety of devices, such as  lamps inside or outside the house,lighting for bird cages and aquariums, sump pumps, battery chargers, etc.   If you need to control something over a longer period than the standard 24 hours, you can use two timers with the second one plugged  into the first one (see photos). To determine what you can do with this arrangement, you  first need to determine how often the load  needs to be switched. For example, if the  first timer has 48 tabs the shortest ‘on’ time  is 30 minutes in 24 hours. This means that the  second timer will run for 30 minutes every 24 hours, so the maximum duration of a full cycle is 48 days. A device such as a charger for diving torches can be connected to the second timer. To prevent the ‘on’ time of the second timer from e...

Circuit Diagram  Description Wound on a 3 foot length of PVC pipe, the long loopstick antenna was an experiment to try to improve AM radio reception without using a long wire or ground. It works fairly well and greatly improved reception of a weak station 130 miles away. A longer rod antenna will probably work better if space allows. The number of turns of wire needed for the loopstick can be worked out from the single layer, air core inductance formula: Inductance = (radius^2 * turns^2) / ((9*radius)+(10*length)) where dimensions are in inches and inductance is in microhenrys. The inductance should be about 230 microhenrys to operate with a standard AM radio tuning capacitor (33-330 pF). The 3 foot PVC pipe is wound with approximately 500 evenly spaced turns of #24 copper wire which forms an inductor of about 170 microhenrys, but I ended up with a little more (213uH) because the winding spacing wasn't exactly even. A secondary coil of about 50 turns is wound along the length of th...