This is my first time working with integrated circuits. I have lots of experience with electro-mechanical wiring but such things as 555/556 timers and transistors are new to me. I'm building a paintball gun known in our world as a Spimmy.
My particular gun will operate off a 9V battery and power a 5V 4.7W solenoid/valve that will be activated by the trigger circuit to control the firing of the paintball. The opening and closing of the solenoid must be held to 9ms which will be controlled by a 556 timer. I've worked out the math for the various resistors-potentiometers that are connected to the timer and feel confident about that.
My plan is to buy my parts from All Electronics and, sorting through their stock, I had to use a fairly large capacity transistor to meet the requirements of the 5V 4.7W solenoid. The transistor specs are Pmax 100V, IcMax 6A, VceMax 65W, Hf, 15@ 3V, 4A, VceSat 1.5@600mA, 6A. This is the smallest transistor they carry that seems to work with my solenoid. But I know bigger isn't always better. Is this OK or should I look for something different.
The circuit for the transistor is in the top right corner of the schematic.
My particular gun will operate off a 9V battery and power a 5V 4.7W solenoid/valve that will be activated by the trigger circuit to control the firing of the paintball. The opening and closing of the solenoid must be held to 9ms which will be controlled by a 556 timer. I've worked out the math for the various resistors-potentiometers that are connected to the timer and feel confident about that.
My plan is to buy my parts from All Electronics and, sorting through their stock, I had to use a fairly large capacity transistor to meet the requirements of the 5V 4.7W solenoid. The transistor specs are Pmax 100V, IcMax 6A, VceMax 65W, Hf, 15@ 3V, 4A, VceSat 1.5@600mA, 6A. This is the smallest transistor they carry that seems to work with my solenoid. But I know bigger isn't always better. Is this OK or should I look for something different.
The circuit for the transistor is in the top right corner of the schematic.
Attachments
-
15.7 KB Views: 59