PCB is DONE. Wooooooooot 8)
Assembly procedure:
(During assembly, please note down any errors in the PCB (clashing components etc.) / general comments and let me know PLEASE!)
Power Supply
============
1.) Bolt on the mains Inlet socket CON1 & then solder it in.
2.) Pulg it into the mains, remove mits, switch on.
Gone bang? No, phew. If it does let me know.
3.) Solder in mains switch SW1, mains fuse FSE1 and transformer TRANS1. Insert 1A fuse into holder and place cap on fuse holder.
4.) Pulg it into the mains, remove mits, switch on.
Gone bang? No, phew. If it does let me know.
5.) Solder in the bridge rectifier BR1 (nothing the polarity), 1000uF capacitor C2 (make sure the polarity is CORRECT) and 100nF capacitor C1.
6.) Pulg it into the mains, remove mits, switch on.
Gone bang? No, phew. If it does let me know.
If you can, measure the voltage across 1000uF capacitor C2. Shouldn't be more than about 20V DC.
If it isn't STOP & let me know what it is!
7.) Solder in regulator IC1 (pop rivet provided), 100nF capacitor C3, 10uF C4.
8.) Pulg it into the mains, remove mits, switch on.
Gone bang? No, phew. If it does let me know.
Measure the voltage across 10uF capacitor C4 or 100nF C3. It should be pretty damn close to 12V DC.
If it isn't STOP & let me know what it is!
9) Solder in 1K resistor R1 and red LED LED1.
10) Pulg it into the mains, remove mits, switch on.
Gone bang? No, phew. If it does let me know.
The red LED should be on indicating power. If not the LED may be incorrectly inserted, so remove it, reverse it and solder it back in.
You won't damage it by putting it in the wrong way around. Copy & paste this for all LEDs
OK, with power on, check voltage supply to the ICs:
IC2: pin7 = GND, pin14 = +ve = +12V
IC4 & IC3: pin1 = GND, pin8 = +ve = +12V
If the voltages are correct for the supply pins carry on.
MonoStable
==========
Now you can confidentally solder in the other bits & bobs:
R8,7,5,6,4,2, C10,8,5, D1,2, LED3,4, CON2,4, SW2 (on extention wires if needs be), RLY1
VAR1 - use extention wires. Connect middle pin to middle pin, outer pins to outer pins.
Testing the Monostable
======================
Don't plug the pump in yet.
Wire up the float switch to screw terminal block CON4.
Turn the POT fully anti-clock wise.
Plug into mains, switch on SW1 (does SW1 work to switch it off? If not check).
Does switching SW2 to 'disable' illuminate LED4?
Switch SW2 to enable (LED4 should be off).
Play with the float switch: Does LED3 indicate correct functionality? It should come on
and STAY on for at least 1.1 secs and then after a set period of time, GO OFF!
If everything seems fine, Turn POT VAR1 fully clockwise. Does the time increase or decrease?
If the time decreases, swap the two outer wires.
Connect a pump and see if it works!
Can you set the time the pump is on from 1.1 secs to 110 secs? Indeed, is 110secs long enough?
Alarm (optional)
================
Assemble & solder in all the other parts.
Testing the Alarm
=================
Testing is a bit dangerous:
With the mains lead DISCONNECTED remove the cover of the relay if you can.
!! BE CAREFUL ONCE THE COVER IS OFF LIVE PARTS EXPOSED !!
With the unit swiched on and NO demand for topping up with SW2 in whatever position (test it for both),
use an isulated screwdriver and push the relay contacts over such that the pump comes on. Red LED2 should
now start flashing and if an alarm is connected, it should be going on & off.
Replace the cover of the mains relay once testing complete.
===============
Good luck,
Andy
[Edit]: Got C1 & C2 arse about face. Thanks Sophos...