All posts on May, 2009
The idea is to add some kind of projector capability to mobile phone (e.g. iPhone) that isnโt too complex or expensive. Instead of using an expensive mini projector. This project use lasers instead to any bitmap font using a matrix of laser points, which is controlled by iPhone.[more]
Sun mirror is a solar powered artbot that uses a popular circuit called a “Solar Engine”. The circuit only uses two transistors, one flashing led, one resistor, one capacitor. Start by connecting your parts on a protoboard to be sure all the parts work together. Fixing a non-working circuit after building it will make a mess of things.[more]
This project combines a battery-operated doorbell, antique phone, Arduino, and subscriber line interface circuit (SLIC) to make a wireless doorbell. Readers are taken through basic phone restoration, creation of a custom doorbell button transmitter, modification of the receiver, workings of the SLIC, and description of the Arduino code.[more]
Five by Twenty : A 5 tubes SSB QRP Transceiver for 20m Ham band.It is a true SSB transceiver built around just 5 vacuum tubes, with no transistors nor ICs. Superhet receiver with AGC and S-meter drives a loudspeaker, 5W transmitter. Very stable VXO uses CB crystals to cover 20m Ham band.[more]
This design use to boost the output power of low power FM broadcast band exciters, a number of these are available commercially, both as kits and ready made. The amplifier design is based on the recently introduced (1998) Motorola MRF171A MOSFET.The initial feasibility was performed using a linear RF and microwave simulation package, specifically Supercompact. [more]
