Friday, October 31, 2008

Car Wireless Alarm

Looking for wireless alarm for your car ?

This FM radio-controlled anti- theft alarm can be used with any vehicle having 6- to 12-volt DC supply system. The mini VHF, FM transmitter is fitted in the vehicle at night when it is parked in the car porch or car park.

The receiver unit with CXA1019, a single IC-based FM radio module, which is freely available in the market at reasonable rate, is kept inside. Receiver is tuned to the transmitter's frequency. When the transmitter is on and the signals are being received by FM radio receiver, no hissing noise is available at the output of receiver. Thus transistor T2 (BC548) does not conduct. This results in the relay driver transistor T3 getting its forward base bias via 10k resistor R5 and the relay gets energised.

When an intruder tries to drive the car and takes it a few metres away from the car porch, the radio link between the car (transmitter) and alarm (receiver) is broken. As a result FM radio module gene-rates hissing noise. Hissing AC signals are coupled to relay switching circ- uit via audio transformer. These AC signals are rectified and filtered by diode D1 and capacitor C8, and the resulting positive DC voltage provides a forward bias to transistor T2. Thus transistor T2 conducts, and it pulls the base of relay driver transistor T3 to ground level. The relay thus gets de-activated and the alarm connected via N/C contacts of relay is switched on.

If, by chance, the intruder finds out about the wireless alarm and disconnects the transmitter from battery, still remote alarm remains activated because in the absence of signal, the receiver continues to produce hissing noise at its output. So the burglar alarm is fool-proof and highly reliable.

Schematic



http://www.electronic-circuits-diagrams.com/alarmsimages/alarmsckt12.shtml

Thursday, October 30, 2008

12V - 40W Fluorescent Lamp

Lampu Neon 12 V - 40 W

If you don't satisfied with the 12VDC Fluorescent Lamp and wanna build the larger one, you can make this.

This 40W fluorescent lamp inverter allows you to run 40W fluorescent tubes from any 12V source capable of delivering 3A and can be used to light regular or blacklight tubes.


Schematic




Parts


Part
Total Qty.
Description
Substitutions
R11180 Ohm 1W Resistor
R2147 Ohm 1/4W Resistor
R312.2 Ohm 1W Resistor (only needed once)
C1, C22100uF 16V Electrolytic Capacitor
C31100nF Ceramic Disc Capacitor
Q11TIP 3055 or 2N3055 or equivalent
L11See "Notes"
T11See "Notes"
MISC1Wire, Case, Board, Heatsink For Q1, heatshrink, AM antenna rod for coil


Notes

  1. Email Bart Milnes with questions, comments, etc.
  2. Wind L1/T1. You will need an AM antenna rod that is about 60mm (2.5 inches) long to wind T1/L1 on. T1/L1 are wound on the same core. Shrink a layer of heatshrink over the core to insulate it. Leave 50mm of wire at each end of the coils.
    Primary: Wind 60 turns of 1mm diameter enamelled copper wire on the first layer and put a layer of heatshrink over it.
    Feedback: Wind 13 turns of 0.4mm enamelled copper wire on the core and then heatshrink over that.
    Secondary: This coil has 450 turns of 0.4mm enamelled copper wire in three layers. Wind one layer and then heatshrink over it. Do the same for the next two.
    Transformer/Inductor Winding
  3. Calibrate/test the circuit. To calibrate/set up the circuit connect the 2.2 Ohm 1W resistor (R3) in series with the positive supply. Connect a 40W fluorescent tube to the high voltage ends of the transformer. Momentarily connect power. If the tube doesn't light immediately reverse the connections of L1. If the tube still doesn't work, check all connections. When you get the tube to light remove the 2.2 ohm resistor and the circuit is ready for use. You will not need R3 again.
  4. This circuit is designed for 220V lamps. It will work with 120V units just fine, but will shorten the life of the tube.
  5. This page has been extensively rewritten by Bart Milne. (15/3/01)

Jika Anda kurang puas dengan lampu neon 12 VDC dan ingin membuat yang dayanya lebih besar, Anda bisa membuat yang satu ini.

Inverter lampu neon 40 W ini bisa menyalakan lampu neon 40 W hanya dengan power suplai 12 V berarus 3 A, bisa neon biasa atau neon tabung hitam.

Catatan:

12VDC Fluorescent Lamp

Lampu Neon 12 V DC

If you are looking for Fluorescent Lamp Driver using ordinary transformer, here it is.
It uses a normal 120 to 6V stepdown transformer in reverse to step 12V to about 350V to drive a lamp without the need to warm the filaments.


Schematic



Parts


Part
Total Qty.
Description
Substitutions
C11100uf 25V Electrolytic Capacitor
C2,C320.01uf 25V Ceramic Disc Capacitor
C410.01uf 1KV Ceramic Disc Capacitor
R111K 1/4W Resistor
R212.7K 1/4W Resistor
Q11IRF510 MOSFET
U11TLC555 Timer IC
T116V 300mA Transformer
LAMP14W Fluorescent Lamp
MISC1Board, Wire, Heatsink For Q1

Notes:

  1. Q1 must be installed on a heat sink.
  2. A 240V to 10V transformer will work better then the one in the parts list. The problem is that they are hard to find.
  3. This circuit can give a nasty (but not too dangerous) shock. Be careful around the output leads.


Anda mencari rangkaian lampu neon 12 V DC dengan menggunakan trafo biasa? Ini dia.

Trafo yang digunakan seperti trafi biasa dengan tegangan 120 ke 6 V yang digunakan terbalik sehinggga dengan tegangan primer 12 V menghasilkan tegangan output 350 V untuk menyalakan lampu neon tanpa memanaskan filamen.

Catatan:
  1. Q1 harus meenggunakan heatsink (peredam panas)
  2. Lebih baik menggunakan trafo 240 ke 10 V, tapi masalahnya susah didapat :-)
  3. Hati-hati dengan tegangan keluaran, bisa menyetrum!