DC to AC Inverter using 555

Inverter DC ke AC Menggunakan IC 555


This DC-to-AC inverter schematic produces an AC output at line frequency and voltage. The 555 is configured as a low-frequency oscillator, tunable over the frequency range of 50 to 60 Hz by Frequency potentiometer R4.

The 555 feeds its output (amplified by Q1 and Q2) to the input of transformer T1, a reverse-connected filament transformer with the necessary step-up turns ratio. Capacitor C4 and coil L1 filter the input to T1, assuring that it is effectively a sine wave. Adjust the value of T1 to your voltage.

The output (in watts) is up to you by selecting different components.

Input voltage is anywhere from +5V to +15Volt DC, adjust the 2700uF cap's working voltage accordingly.
Replacement types for Q1 are: TIP41B, TIP41C, NTE196, ECG196, etc. Replacement types for Q2 are: TIP42B, TIP42C, NTE197, ECG197, etc. Don't be afraid to use another type of similar specs, it's only a transistor... ;-)

Parts List:

R1 = 10K
R2 = 100K
R3 = 100 ohm
R4 = 50K potmeter, Linear
C1,C2 = 0.1uF
C3 = 0.01uF
C4 = 2700uF
Q1 = TIP41A, NPN, or equivalent
Q2 = TIP42A, PNP, or equivalent
L1 = 1uH
T1 = Filament transformer, your choice

If the whole thing is working, good. If not, relax and don't get frustrated. Do the following checks:

1. You have connected the filament transformer in REVERSE yes?
2. If not, disconnect the power and reverse. If you have, disconnect the transformer and measure the voltage after L1 and ground.
3. Just in case, GROUND for this circuit is same as negative (-).
4. Q1/Q2 are oposites, e.i. npn/pnp.
5. Is your 555 perhaps defective? Disconnect R3 from pin 3 and check pin 3 for a pulse.
6. Check your transistors to make sure they are not defective.

Error fix: Pin 7 and 2 were reversed. Original pinout was correct.



Rangkaian Inverter DC-AC ini menghasilkan tegangan keluaran AC seperti tegangan jala-jala. IC 555 dikonfigurasikan sebagai osilator frekuensi rendah. Frekuensi bisa diubah dari 50 ke 60 Hz dengan mengubah potensiometer frekuensi R4.

Theft preventer alarm

This circuit utilising a 555 timer IC can be used as an alarm system to prevent the theft of your luggage, burglars breaking into your house etc. The alarms goes ON when a thin wire, usually as thin as a hair is broken.

The circuit is straightforward. It uses a 555 IC wired as an astable multivibrator to produce a tone of frequency of about 1kHz which gives out a shrill noise to scare away the burglar.

The wire used to set off the alarm can be made of a thin copper wire like SWG 36 or higher.
You can even use single strands of copper form a power cable.

The circuit operates on a wide range of voltages from 5V to 15V.

The speaker and the circuit could be housed inside a tin can with holes drilled on the speaker side for the sound to come out.

Rangkaian yang menggunakan IC timer 555 ini dapat digunakan sebagai alarm untuk mencegah pencuri menggondol barang-barang atau masuk ke rumah Anda. Alarm akan menyala (ON) ketika kawat tipis (biasanya setipis rambut) putus.

Rangkaian ini menggunakan IC 555 yang dikawati menjadi multivibrator yang tidak stabil untuk menghasilkan frekuensi sekitar 1 kHz yang terdengar cukup menakutkan perampok.

Kabel tipis yang dimaksudkan untuk mematikan alarm dapat dibuat dari kawat tembaga tipis seperti SWG 36 atau bisa juga serat kawat tembaga dari kabel power.

Rangkaian ini beroperasi dalam jangkauan tegangan yang cukup besar yaitu antara 5 hingga 15 V.

Speaker dan rangkaian dapat dimasukkan ke dalam kaleng dengan diberi lubang di depan speaker agar suara bisa keluar.

http://www.electronic-circuits-diagrams.com/alarmsimages/alarmsckt3.shtml