Electronic projects




you are here: home page :: projects :: Timers & oscillators :: oscillators :: Electronic Canary

Electronic Canary

Feeling chirpy? Attract new friends with this modified hartley oscillator. You could also use it as a replacement doorbell.

Circuit diagram
url=projects/282/bigs/canary.gif][/url]

Notes:
This circuit is a modified hartley oscillator with a couple of extra components included. The transformer is a small audio transformer, type LT700. The primary is center tapped with an impedance of 1Kohms at 1KHz . The secondary has an impedance of 8 ohms. The inclusion of R1 and C1 give this oscillator its characteristic "chirp". As the 100u capacitor charges via the 4.7K resistor, R1 the bias for the transistor is cut off. This causes the oscillation to stop, the capacitor discharges through the base emitter circuit of the transistor and oscillations start again. Altering these components alters the frequency of the chirp. The chirp is also voltage dependent. When the push button switch is operated the 100u capacitor is charged. When its released, the oscillation decays and the chirp becomes faster. [

author:
e-mail:
web site: http://www.zen22142.zen.co.uk
project categories:
folder Audio (49)
folder Power & high voltage (43)
folder Radio (23)
folder Light & LED (31)
folder Tools & measurement (40)
folder Telephone (18)
folder Automotive (10)
folder Microcontrollers (12)
folder Sensors & control (47)
folder Timers & oscillators (40)
folder Miscellaneous (26)

StumbleUpon button

Share this page
Bookmark and Share
project subcategories:
All subcategories
timer circuits
oscillators

similar projects:
1KHz Sinewave Generator
Adjustable High/Low Frequency Sine wave generator
Electronic Siren
Function Generator
Insect Repellant
Low-distortion Audio-range Oscillator
Mini Metronome
Precision Metronome and Pitch generator
Reverse Bias Oscillator
Self-powered Sine to Square wave Converter

recently added projects:
Doorbell for the Deaf
High Quality Intercom
Combinational Conjuring Trick
POT-PLANT POWER
Ultrasonic Dog Whistle
Quiz Circuit
LED Torch
Insect Repellant
Speaker Microphone Circuit
Magic Wand Conjuring Trick.

most popular projects:
Led display digital Voltmeter
500W low cost 12V to 220V inverter
Low pass filter - Subwoofer
Metal Detector
Basic UPS Power Supply
2N3055 Power Amplifier
High And Low Voltage Cut Off With Time Delay
200W audio amplifier
LED Torch
100W RMS Amplifier


DIY Electronics Projects

Promote Your Page Too