All posts on January, 2010
Posted on 31 Jan 2010
The fish feeding timer is based on a simple monostable 555 circuit and a relay to drive the load (the return pump in this case). The circuit is setup as simple monostable 555 multivibrator, a.k.a a one shot trigger or timer.The timing period can be adjusted by turning the potentiometer.[more]
Posted on 18 Jan 2010
The development team of this project aim to develop sensors for measuring ionic contaminants (pH, Chloride ion, Potassium, Mercury, Fluoride, Arsenic, Lead, Iron, Cadmium, Sulphate and Nitrate) as well as for some physical parameters (like conductance and salinity) for water quality testing. Polysensor can now measure six parameters simultaneously (pH, NO3-, Cl-, EC, TDS and salinity). [more]
Posted on 09 Jan 2010
This is a simple Pulse Width Modulation Controller using a 555 that can go from about 1% to 99% Duty Cycle and Control High Currents to run lights or motors. This particular circuit was built for 12 volt DC operation, but can be operated at other voltages assuming you don’t exceed the 555 operating supply voltage.[more]
Posted on 09 Jan 2010
This RGB LED driver uses logic level ‘N’ channel high power MOSFETs which allow it to control LED arrays or lamps at up to 5 amps per channel without heatsinks. The main unit control by PIC16F683. The circuit will operate from a supply voltage in the range 9 to 24 volts. [more]