Dear sirs,
thank's for the replies!
I try to explain better my problem.
The scenario is illustred at this image.
**broken link removed**
A water spot must be sprayed at the pressur of a pushbutton.
My power supply is a 12V DC car battery.
I made a circuit for control a 12V DC solenoid valve (the MCU control the relay) that must be open for some milliseconds (fig. 1).
A 12V DC water pump is used (and run "forever") for put in pressure the water pipe. The pump needs about 7 Ampere when running.
A linear voltage regulator is used for give 3.3V DC from the 12V DC car battery, used for supply the control circuit.
My problem born when I close the circuit, all start for 1 or 2 seconds and then the MSP430 and display retroillumination coocks!
I suppose this is caused by the water pump current consumption and I made a little change to my circuit (fig. 2).
Now I have a second 9V battery with a second power on switch that supply only control circuit and all seem to function correctly.
My question is: how I can obtain a safe 3.3V from the 12V DC car battery without all listed problems?
Thank you in advance,
Silvio Vallorani.
**broken link removed**
**broken link removed**
thank's for the replies!
I try to explain better my problem.
The scenario is illustred at this image.
**broken link removed**
A water spot must be sprayed at the pressur of a pushbutton.
My power supply is a 12V DC car battery.
I made a circuit for control a 12V DC solenoid valve (the MCU control the relay) that must be open for some milliseconds (fig. 1).
A 12V DC water pump is used (and run "forever") for put in pressure the water pipe. The pump needs about 7 Ampere when running.
A linear voltage regulator is used for give 3.3V DC from the 12V DC car battery, used for supply the control circuit.
My problem born when I close the circuit, all start for 1 or 2 seconds and then the MSP430 and display retroillumination coocks!
I suppose this is caused by the water pump current consumption and I made a little change to my circuit (fig. 2).
Now I have a second 9V battery with a second power on switch that supply only control circuit and all seem to function correctly.
My question is: how I can obtain a safe 3.3V from the 12V DC car battery without all listed problems?
Thank you in advance,
Silvio Vallorani.
**broken link removed**
**broken link removed**