Hi,

            I have a system that has to use two voltages, 5V and 12V. The 5V
need to supply 100mA max, and the 12V have peaks of 2A and 0.75A continuos
current. As you might have already guess the 12V are supplying a DC motor.

 

            I currently have a full bride and a small cap + a 7805 for the
5V section, and, coming from another winding on the transformer, another
full bridge + a 4700 cap. The transformer winding is 12VAC for the motor,
so, once rectified, the motor gets around 16~17 Volts, which was fine
because the motor speed increase and that was a good thing.

 

            Last detail: The motor works usually 4 times a day for 10
seconds max each day.

 

            Now, I need to simplify the design. I need to eliminate the
power supply board and I don't have much space on the board that the pic is
in. Everything is SMD I already managed to include the PIC supply on that
board but I having trouble redefining the DC motor supply for lower cost and
lower component count.

 

            At this moment, the speed of the motor is not a mayor concern as
it is the torque. I made a simple 1 diode rectifier, with no cap, thinking
that the motor doesn't really need a pure continuos current, but I lost a
lot of torque. I can increase the transformer output voltage, but I'm not
quite sure it's the right move. What do you think it would be the most cheap
but reliable approach to make the DC motor work?

 

            Kind regards,

 

Mauricio Jancic

Janso Desarrollos - Microchip Consultants Program Member

info@janso.com.ar

www.janso.com.ar

(54) 11 - 4542 - 3519

 

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist