Bass-treble tone control circuit

he LM1036 is a DC controlled tone (bass/treble), volume and balance circuit for stereo applications in car radio, TV and audio systems. An additional control input allows loudness compensation to be simply effected. Four control inputs provide control of the bass, treble, balance and volume functions through application of DC voltages from a remote control system or, alternatively, from four potentiometers which may be biased from a zener regulated supply provided on the circuit. Each tone response is defined by a single capacitor chosen to give the desired characteristic.

FET Audio Mixer

This simple circuit mixes two or more channels into one channel (eg. stereo into mono). The circuit can mix as many or as few channels as you like and consumes very little power. The mixer is shown with two inputs, but you can add as many as you want by just duplicating the "sections" which are clearly visible on the schematic.

• R1, R3 10K Pot
• R2, R4 100K 1/4 W Resistor
• R5 6.8K 1/4 W Resistor
• C1, C2, C3 0.1uF Capacitor
• Q1 2N3819 Junction FET
• MISC Wire, Shielded (Metal) Case, Phono Or Other Plug For Output

Personal alarm

• R1 330K 1/4W Resistor
• R2 100R 1/4W Resistor
• C1 10nF 63V Polyester or Ceramic Capacitor
• C2 100µF 25V Electrolytic Capacitor
• Q1 BC547 45V 100mA NPN Transistor
• Q2 BC327 45V 800mA PNP Transistor
• SW1 Reed Switch and small magnet (See Notes)
• SPKR 8 Ohm Loudspeaker (See Notes)
• B1 3V Battery (two A or AA cells wired in series etc.)

Door Alarm

• R1 1M 1/4W Resistor
• R2 3K3 1 or 2W Resistor (See Notes)
• R3 10K 1/2W Trimmer Cermet (See Notes)
• R4 33K 1/4W Resistor
• R5 150K 1/4W Resistor
• R6 2K2 1/4W Resistor
• R7 22K 1/4W Resistor
• R8 4K7 1/4W Resistor
• C1,C2 10nF 63V Ceramic or Polyester Capacitors
• C3 10pF 63V Ceramic Capacitor
• C4,C6 100nF 63V Ceramic or Polyester Capacitors
• C5 2µ2 25V Electrolytic Capacitor
• C7 100µF 25V Electrolytic Capacitor
• D1,D2,D4 1N4148 75V 150mA Diodes
• D3 5 or 3mm. Red LED
• Q1,Q2,Q3,Q5 BC547 45V 100mA NPN Transistors
• Q4 BC557 45V 100mA PNP Transistor
• L1 (See Notes)
• L2 10mH miniature Inductor
• Hook (See Notes)
• BZ1 Piezo sounder (incorporating 3KHz oscillator)
• SW1,SW2 SPST miniature Slider Switches
• B1 9V PP3 Battery
• Clip for PP3 Battery

Emergency Light & Alarm

Warning! The circuit is connected to 220Vac mains, then some parts in the circuit board are subjected to lethal potential!. Avoid touching the circuit when plugged and enclose it in a plastic box.

Powered by two AA NI-CD batteries
 Four switchable options

• R1 220K 1/4W Resistor
• R2 470R 1/2W Resistor
• R3 390R 1/4W Resistor
• R4 1K5 1/4W Resistor
• R5 1R 1/4W Resistor
• R6 10K 1/4W Resistor
• R7 330K 1/4W Resistor
• R8 470R 1/4W Resistor
• R9 100R 1/4W Resistor
• C1 330nF 400V Polyester Capacitor
• C2 10µF 63V Electrolytic Capacitor
• C3 100nF 63V Polyester Capacitor
• C4 10nF 63V Polyester Capacitor
• D1-D5 1N4007 1000V 1A Diodes
• D6 LED Green (any shape)
• D7 1N4148 75V 150mA Diode
• Q1,Q3,Q4 BC547 45V 100mA NPN Transistors
• Q2,Q5 BC327 45V 800mA PNP Transistors
• SW1,SW2 SPST Switches
• SW3 SPDT Switch
• LP1 2.2V or 2.5V 250-300mA Torch Lamp
• SPKR 8 Ohm Loudspeaker
• B1 2.5V Battery (two AA NI-CD rechargeable cells wired in series)
• PL1 Male Mains plug