Showing posts with label 3v. Show all posts
Showing posts with label 3v. Show all posts
Thursday, November 6, 2014
3V Sweeping Siren Alarm
The circuit uses a LTC1799 precision frequency generator from Linear Technology. A 74HC14 hex Schmitt trigger from Texas Instruments is also used to perform several other functions. One section is wired as a simple 7Hz square wave oscillator. The triangle waveform across that capacitor generates the low frequency sweeping signal for the siren. Two resistors bias the LTC1799 for a center frequency of about 2KHz. A flyback DC to DC converter circuit, produces a 40v peak signal, which is turned on and off according to the output of the LTC1799.
The output is connected to a quality piezoelectric beeper, which has a resonant frequency of about 2.5KHz. The result is a siren which is quite loud but draws only 40ma from a 3v supply. A piezoelectric device from Kobitone, part number 254-PB515-ROX, (Mouser part number 245-PB516) shown above works well. If you want something much smaller, although not quite as loud, try the Murata PKM17EPP-2002-BO shown above (Digikey part number 490-4688).Click on Schematic below to view PDF version of this Circuit
Thursday, October 9, 2014
Switching power supply dual voltage 5v and 3 3v by LM2575 LM1117
Here is circuit Switching power supply dual voltage, output 5V 1A and 3.3V 1A.
Use IC LM2575 SIMPLE SWITCHER 1A Step-Down Voltage Regulator ,and IC LM1117 is 800mA Low-Dropout Linear Regulator. Volt suppy 9V – 60V
Detail more see to image circuit.
Thursday, August 21, 2014
3V to 40 Volt DC Converter Circuit
Switching regulator subsystems intended for use asdc to dc converters. 3V to 40 Volt DC Converter circuit | The use of switching regulators is becoming more pronounced over that of linear regulators because the size reductions in new equipment designs require greater conversion efficiency. Another major advantage of the switching regulator is that it has increasednapplication flexibility of output voltage. The output can be less than, greater than, or of opposite polarity to that of the input voltage.
![3V]()
![Switching]()
The MC34063 series is a monolithic control circuit containing all the active functions required for dc to dcconverters. This device contains an internal temperature compensated reference, comparator, controlled duty cycle oscillator with an active peak current limit circuit, driver, and a high current output switch. This series was specifically designed to be incorporated in step–up, step–down and voltage–inverting converter applications. These functions are contained in an 8–pin dual in–line package.
· Wide Input Voltage Range 3 V to 40 V
· Precision Internal Reference 2%
· High Output Switch Current Up to 1.5 A
· Short-Circuit Current Limiting
· Adjustable Output Voltage
· Low Standby Current
· Oscillator Frequency Up to 100 kHz
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