Water Level Alarm

Components:

                Resistor                : R 150k

                Capacitor             : C1 0.005 µF

                                            : C2 0.01 µF

                Transistor             : TR1 BC108

                                            : TR2 2SB 178

                Speaker 2 Inch/5 ohm

Water level alarm can be used to knowing the surface of the water in water container or water Toren. If water in the container touched the sensors so the alarm will make a sound. This sound is notification when water container was full and you can turn off the water pump.

The amplifier circuit High Tone (Treble)

Components:

Resistor                                : R1 150k

                                            : R2 470k

                                            : R3 2k2

                                            : R4 10k

Potensiometer                      : RV 10k tipe A

Capacitor                             : C1 0.05µF

                                            : C2 0.47µF 

                                            : C3 3n3F

Transistor                             : Tr1 BC 108

If your sound system or amplifier treble tone was already weak, you can create a circuit like the picture on the side. In this case the OUT channel can be connected directly with loundspeaker.

Super Filter

Components:

            Resistor                                        : R1 30 ohm

                                                                : R2 27k

                                                                : R3 1k

                                                                : R4 10 ohm

                                                                : R5 1k

Potentiometer                               : VR 1k

Capacitor                                     : C1 1000 µF / 50V

                                                    : C2 1000 µF / 50V

                                                    : C3 1000 µF / 50V

Transistor                                     : TR1 2N3054

                                                    : TR2 2N3054

Super filter is very suitable used to muffle the noise from power supply. With super filter you can muffle noise until 1:1 and this series must install before strengthener connecting structure.

Factory Siren

Components :

                Resistor            : R1 6k8

                            : R2 100k

                            : R3 3k3

                            : R4 22k

                            : R5 1k

Trimpot                : RV 1k

Capacitor             : C1 4.7µF/10V

                            : C2 0.1µF/15V

Transistor             : Tr1 FCS 9013

                            : Tr2 FCS 9012

SCR                     : MEU 21

Speaker                8Ω 4 inch

This circuit is a siren tone generated by tone generator that generated by the two transistors TR1 and Tr2.
With about 500-100Hz frequency will produce an excellent sound sirens are used as signs began to come to work and marks a break from an office or factory.