I'm designing an embedded system with 4 parts:
-Power supply from a 6V battery.
-6V solenoid.
-5V uController.
-A wireless receiver (Haven't decided which one to use yet).
Here's the problem: The uController can only operate up to 5.5V (and it's not recommended to do so); so I need to lower the supply voltage to a typical 5V. I tried using a Zener diode with a resistor to obtain 5V since a regulator is useless without a higher input voltage. However, the wireless module won't be always on and the current consumption varies greatly, whenever the current consumption drops, it ends up either as a voltage rise or being dissipated as heat by other resistors (Which makes me waste precious battery charge
); if the current consumption rises, the voltage drops.
In other words, what I need is a way to automatically regulate the input current. I immediately thought of a variable resistor which could be made with FET's, PIN diodes or a photoresistor, however, I do not know how to decrease resistance when voltage drops, but keeping voltage within 5V.
What's the most effective approach to solve this problem? The less components needed the better.
Hope anyone can point me in the right direction. Thanks,
-Power supply from a 6V battery.
-6V solenoid.
-5V uController.
-A wireless receiver (Haven't decided which one to use yet).
Here's the problem: The uController can only operate up to 5.5V (and it's not recommended to do so); so I need to lower the supply voltage to a typical 5V. I tried using a Zener diode with a resistor to obtain 5V since a regulator is useless without a higher input voltage. However, the wireless module won't be always on and the current consumption varies greatly, whenever the current consumption drops, it ends up either as a voltage rise or being dissipated as heat by other resistors (Which makes me waste precious battery charge
In other words, what I need is a way to automatically regulate the input current. I immediately thought of a variable resistor which could be made with FET's, PIN diodes or a photoresistor, however, I do not know how to decrease resistance when voltage drops, but keeping voltage within 5V.
What's the most effective approach to solve this problem? The less components needed the better.
Hope anyone can point me in the right direction. Thanks,