Originally Posted by
RTJ_Nair
What I have in mind is to build a microcontroller that will generate the PWM and additionally an independent clock that triggers the H-bridge. Two settable frequencies thus can be at our disposal. One to set the PWM frequency (not very useful) and the second to set the alternating frequency (effects yet to be explored). I have almost completed the microcontroller coding incorporating the RPM-DUTYCYCLE relationship (explained earlier) and the alternating frequency idea which came up recently. It will have an LCD and 4 push buttons featuring the following,
1. Amps-indication
2. RPM-indication
3. Voltage-indication
4. Dutycycle-indication
5. MOSFET Temperature-indication or can be cell temperature (range will be from 0 to 150 deg C)
6. RPM-low (NL)-settable on the fly
7. RPM-high (NH)-settable on the fly
8. FAN activation temperature-settable on the fly
9. PWM frequency-settable on the fly
10. LOW VOLTAGE (FAULT) -settable on the fly for PWM shutdown
11. HIGH TEMPERATURE (FAULT) - settable on the fly for PWM shutdown
12. OSCILLATOR frequency-settable on the fly for the time being and if proven beneficial, can be made automatic.
The above features are purely for R & D and might not be needed for general use. Let us see if any success can be made.
Regarding the effect of changes in ambient condition, the microcontroller and the MOSFET module/H-bridge can be separated. The microcontroller can be inside the cabin and the latter inside the engine compartment. Both can be easily linked using an FRC5 connector or similar.
To build the inductor, I need to know the approximate cell capacitance for a 4"x4", +NNNNN-, 7 plate drycell. Any info on this will be highly appreciated.
RTJ_Nair