Tahmid
Advanced Member level 6
- Joined
- Jun 17, 2008
- Messages
- 4,764
- Helped
- 1,799
- Reputation
- 3,590
- Reaction score
- 1,662
- Trophy points
- 1,413
- Location
- Berkeley, California
- Activity points
- 30,716
Hi all,
rajudp and sahu wanted to see pics of my inverter that I mentioned earlier in another post, so here it is. For the benefit of the members, I describe the circuit as:
*single microcontroller/controller (ATMEGA16/32)
*no op-amps, only chips are the micro, opto-couplers and regulator (7805)
*low-battery/overload/short-circuit protection
*thyristor controlled battery charger, using the MOSFET body diode as the AC-DC rectifier
*charger maintains the battery voltage (top) between 13.2-13.5v (adjustable) to maximize the battery life
*6-LED display
*Only 93 parts in entire control circuit
*Delay between switchover to prevent inrush current
The method used here, described for those who may benefit from it:
-Initialize all ports and peripherals[ADC, Timers, Compare Modules]
-Initialize interrupts for Timer0 and compare module for
-For PWM, use Timer1 and 16-bit Phase and Frequency Correct PWM mode so the PWM runs completely on the hardware level without need for interaction to keep it running
-The AVR senses whether mains is present or not using a standard opto (4N35).
-If mains present, check battery level
-If battery level < 13.5v (this voltage is set using a pot, so can be easily adjusted), charge at the set current(set with a pot)
-If battery level > 13.5v, stop charging
-While battery > 13.2v, stop charging
-If battery voltage drops instantly start charging again
-Triac based, uses Timer0 and compare module with interrupt for phase angle control for fast charge, never overcharges battery, battery hasn't ever heated up till now and 2 year old battery still gives good backup, so charging algorithm is good for battery life
-Check mains
-If mains absent, initialize Timer and start PWM
-Check battery voltage, stop PWM and indicate on LED when battery falls below 10.8v (this is also set with a pot), response time is fast so a short circuit that produces an instant voltage drop is detected
-Check load level, check against preset level (set with pot) and if too high, shut down and indicate
-Check output voltage, adjust as required
-Check mains
*Coding is done with mikroBASIC PRO for AVR
*All voltages mentioned, eg 13.2v, 13.5v, 10.8v, Overload voltage, etc are all adjustable and set with variable resistors
I will upload the schematic and PCB design soon.
Tahmid.
I see, I didn't do any thing of such, but it maybe a good idea. Anyway, since I used a BTA26 I doubt it's ever gonna blow up and I'm sure my microcontroller isn't misfiring at all, so no problems yet. But doesn't hurt to be safe, you should go ahead and use it.
I really wonder which school you studied and who is/was your english teacher. I would love to study there. I am really appreciating. Ok..anyways, as usual the forum doesnt demand upper case letters unless required and mandatory, and thus you get a warning. You need to correct it before you post anything further on this forum.USE TWO SCR IN ANTI PARLLER DIRECTION WITH PRAPER snubber ,FOR SEFTY REASION MOSFET & CHEK I\P {I\P AC} CURRENT DURING CHARGING WITH TRIAC AND TWO SCR IN ANTI PARLLER DIRECTION . I'M SURE U CAN FOUND REASION OF
blow up UP TRIAC.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?