| ... | ... | @@ -4,6 +4,11 @@ We started with a U.S. Solid Smart Motorized Ball Valve (Model USS-MSV00087). Du |
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- RZ7888 (2A motor control driver IC, SOP-8 package)
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- Activation of the close function of the valve via Y1 NPN transistor (noted in purple below) - tied to pin 1 of the motor control and controlled by pin 6 of the control board
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- Activation of the close function of the valve via Y1 NPN transistor (noted in orange below) - tied to pin 2 of the motor control and controlled by pin 5 of the control board
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- Both transistors are held in the open position with their bases held high by 10Kohm resistors to the 3.3v rail
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- To bring the motor control pins low, the control pin, connected to the emitter of the transistor is toggled from high to low
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- This is an odd construction with no protection between the collectors (biased to 4.7v by 10Kohm resistors in positions R16 and R18 which are connected to the reverse polarity diode on the 5v input
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- Addressed in updated design by connecting the motor control pins 1 and 2 directly to GPIO pins that can sink 200mA as needed.
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- May be advisable to add appropriately sized resistor 1Kohm @ .25W as a precaution.
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- Activation of direction is driven by pulling the appropriate pin to low
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- When both pins are high, the motor is frozen in a fixed position (regardless of the torque on the valve
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## Valve position
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