Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Charge Controller problem

Status
Not open for further replies.

bgd3200

New Member
Hi!
I made a solar charge controller. It worked very well, until I needed to move it to another place and I connected wrong the battery leads to the circuit ... I connected plus to minus and minus to plus. The solar panel was not connected at that moment.

I need to know what parts burned up first, how to find the broken part with a multimeter.

I attached the circuit schematic.

Thank you and sorry for my bad english( it's not my primary language).


C__Data_Users_DefApps_AppData_INTERNETEXPLORER_Temp_Saved Images_555ChargeController2.jpg
 
Connect the circuit to a current limited 12 power supply. Limit the current to about 50 mA more then the current that the relay coil would take. Start by checking the voltage on pin 3 of the 7805 voltage regulator with respect to ground. If it is not about 5 volts then break the connection from this point to the rest of the circuit. Check the voltage again on pin 3 of the regulator. If it is still not about 5 volts then replace the regulator.
If the voltage on pin 3 is about 5 volts then measure the voltage on pins 3 and 7 of the 555 and note the results. Also note if either or both of the LEDs is illuminated. Try pressing the push buttons (One at a time.) Make a note of the results and post them in a reply. It would take too long to post the full tree structure of tests to identify every possible failures or multiple failures.

Les.
 
Voltage measured on 7805 regulator is about 4.95V.

Voltage measured on 555 ic :
- on pin 3: [3.69V]
- on pin 7: [4.04V]

Green ( charging LED) is always on and red (dumping LED) is off.

When i press the charging puss buton, nothing happens.

When i press the dumping button, the red LED(dumping LED) turns on, and turns off when i release the button. So if i hold the dumping button pressed, the red dumping led start to blink ( the blinking looks interrupted, uneven), but the Green charging led don't turn off (it stays on but the light diminishes).
 
I think the 555 has been destroyed by the polarity reversal so this needs replacing. There still could be other faults but you need to work forward trough the circuit. Can you add the component values, transistor types and the relay coil resistance or current rating in your next post.

Les.
 
Parts list:

IC1 - 7805 5 Volt positive Voltage Regulator R3, R4, R5 - 1K Ohm 1/8 Watt 10%
IC2 - NE555 Timer Chip
R6 - 330 Ohm 1/8 Watt 10%
PB1, PB2 - NO Momentary Contact Push Buttons
R7 - 100 Ohm 1/8 Watt 10%
LED1 - Green LED
Q1 - 2N2222 Or Similar NPN Transistor
LED2 - Yellow LED
Q2 - IRF540
RLY1 - 40 Amp SPDT Automotive Relay
C1 - 0.33uF 35V 10%
D1 - 1N4001
C2 - 0.1uF 35V 10%
R1, R2 - 10K Multi-Turn Trim-Pots
R8-R9 - 330 Ohm 1/2 W Resistors

I get the schematic from https://www.mdpub.com/555Controller/

Thank you!
 
Post the results when you have replaced the 555. There is a good chance that Q2 and D1 have also been destroyed and a possibility that Q1 has been destroyed.

Les.
 
Hi bgd3200, I am starting to build based on you reference mdpub's. I am unable to locate the store for the following parts:
R6- 330 ohm 1/8w 10%
&
R7- 100 ohm 1/8w 10%
Could you please let me know the source of the parts. Thanks in advance.
 
This is an international site. Members are from around the world. In order to help you it would help to know which continent you reside.
Do you need it now or can wait for a delivery from overseas. You can fill in the "location" field in your personal details.
 
My bad that I did not mention the continent. I am from USA and I could start to build the circuit board if I have those parts.
 
Last edited:
Colin, could you please throw some light on why they are in the wrong place. Any alternative suggestions.
 
R9 should be placed between R2 and PB1
R8 should be placed between R1 and PB2
R7 is not needed.
All resistors can be 0.25 watt
The output driver can be a simple BD transistor.
 
Last edited:
CHARGE CONTROLLER
This circuit prevents a battery being overcharged. When the battery is charged, the energy from the solar panel is dumped into a LOAD. This load can be a 12v 100watt globe or a high-power resistor.
You only have to dump excess current of your solar panel is capable of fully charging the battery in less than 10 hours.
If it takes 24 hours of sunlight to charge the battery, this is equal to 3 days of illumination and the battery will accept this low rate of charge.
SETTING UP
Use a variable power supply.
You don't need the high wattage resistor or the battery or solar panel or the relay!.
Connect the variable power supply set to 11.9v. Adjust the top 10k pot to turn ON the charging LED.
Increase the voltage to 14.9v and adjust the lower 10k pot to make the dumping LED come on.
Now connect all the components as shown in the circuit and check the voltage levels once more before installing the project.

ChargeController.gif
 
Excellent write up. Throws more light on your indepth knowledge of the system. I am interested in your arrangement too. I just ordered the two components I said I was not able to find the source. I will build one as you suggested and keep you posted. Appreciate your precious time that you put in answering.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top