3V Siren Alarm Schematic

A while back I was challenged by a visitor to the website.  He needed a very loud sweeping siren type audio sound generator powered by 3v.  He tried some of the commercial sirens but they were not very loud when powered by 3v.  He also said that those devices demanded much higher current than he wanted to use.  I gave this problem some thought and came up with a design below.

The 3V Siren Alarm 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 3V Siren Alarm 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.

The 3V Siren Alarm 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).

3V Siren Alarm schematic here:

 

3V Siren Alarm figure

 

9V 10W Mini Audio Amplifier

You can use this powerfull 9V 10W Mini Audio Amplifier in any small audio project. It is very small (6.5 x 4.5 cm).It outputs 10W and uses a 9V battery. 

You can see figure of 9V 10W Mini Audio Amplifier below:

 

9V 10W Mini Audio Amplifier

Class A MOSFET Amplifier Schematic

Class A MOSFET Amplifier Schematic I am using this Class A Amplifier with a 12AU7 based valve preamp. It produces the most purest sound. I have no idea of distortion levels etc. but it has a very fine grain and delicately textured quality. With only one watt of output efficient speakers must be used. Bass is better than the design predicts and the amp drives my 12" 63L based 3-way speakers with ease. 

 See figure of Class A MOSFET Amplifier Schematic below

100 Watt Amplifier Schematic

Power Amplifier

The power amp board has remained unchanged since it was first published in 2002. It certainly isn't broken, so there's no reason to fix it. The photo below shows a fully assembled board. Using TIP35/36C transistors, the output stage is deliberately massive overkill. This ensures reliability under the most arduous stage conditions. No amplifier can be made immune from everything, but this does come close.

12v 1.5w Amplifier

12v 1.5w Amplifier

AUDIO AMP + 3KHz FILTER

AUDIO AMP + 3KHz FILTER
This circuit is the audio amp section for a complete optical transmitter.   The circuit amplifies and filters the voice audio signals from an electret microphone.  The circuit is described in more detail in the receiver section of Dave Johnson's Handbook of Optical Through the Air Communications.

Mini Amplifier LM386

Mini Power amplifier in figure below is series of amplifiers made with LM386 IC. Power amplifier LM386 IC chip is designed as a monolithic power amplifier with low power and low power consumption. Power amplifier CIRCUIT LM386 can be made as a power amplifier with a gain of 20 to 200 times depending on the configuration of the series. Power amplifier circuit using LM386 amplifier IC power in General is a device that requires the amplifier audio with small loudspeakers installed on the device.

Subwoofer Amplifier

This subwoofer amplifier circuit is a power amplifier of BTL (Bridge Told Load) using IC TDA1516BQ. Series amplifier subwoofer has a power output of 25 watts on the load speaker subwoofer with 4 Ohm impedance. Working voltage range amplifier subwoofer is + 12 volts to + 10 volts DC, so it can be used for subwoofer amplifiers in cars. Series subwoofer amplifier in figure below has low tone settings. Featured subwoofer amplifier circuits owned are:

400 Watts MOSFET Amplifier

Circuit power amplifier in figure below is a power amplifier with a power output of OCL 400 watts RMS and using a MOSFET transistor as a power. Circuit power amplifier 400 Watts MOSFET works with DC voltage source symmetrical ± 70 volt up to ± 80 volts DC. Circuit power amplifier 400 Watts works on class AB MOSFET unit using 8 and type IRFP448. The image series and a list of components to create a 400-watt RMS power amplifier with MOSFET of type IRFP448 can be seen in the following figure. Circuit Power Amplifier 400 Watts MOSFET IRFP448

150 Watts Amplifier

Scheme of power amplifier 150 Watts above is a series power amplifier is quite simple with the use of electronic components that are not too much. This arrangement requires only 5 pieces of the transistor as a major component. No option circuit amplifier equalizer on it because it could be said this series is quite so simple, so don't you compare it to the sale of the market which is usually equipped with a sound system and equalizer settings.

50 Watts Amplifier

Series amplifier 50 Watts above is a series of electronic amplifiers that use the transistor as an amplifier. The power supply is a power supply with a voltage of 50 to 60 volts. For this series of sound system equipment was still fairly simple and does not have the adequate equalizer options. But maybe this circuit can be useful when you have a sequence of needs strengthening with a method that is simple and doesn't cost the.

100 Watt Power Amplifier

100 watt power amplifier schematic above is the amplifier circuit is simple enough and use the transistor as an amplifier. On this blog are indeed there have been several postings that contain about transistor amplifier, but I accidentally added a collection series of amplifiers that more options and can support the usefulness of markedly and could add to the knowledge of the amplifier. If you want to make a simple 100 watt amplifier with a capital a more lopsided this series could be a possible option, instead of buying with a much higher price.