I am trying to modify this circuit to detect when my cell phone is receiving an incoming call. I am having trouble figuring out howo the sensor coil will work in this circuit. I also am going to incorporate a band stop filter to use 5kHz as my trial frequency. Can someone help me to understand this????
R1-100K 1/4W Resistor
R2-3K9 1/4W Resistor
R3_1M 1/4W Resistor
C1,C2_100nF 63V Polyester Capacitors
C3_220µF 25V Electrolytic Capacitor
D1_LED Red 10mm. Ultra-bright (see Notes)
D2_1N5819 40V 1A Schottky-barrier Diode (see Notes)
Q1_BC547 45V 100mA NPN Transistor
IC1_7555 or TS555CN CMos Timer IC
L1_Sensor coil (see Notes)
B1_1.5V Battery (AA or AAA cell etc.)
R1-100K 1/4W Resistor
R2-3K9 1/4W Resistor
R3_1M 1/4W Resistor
C1,C2_100nF 63V Polyester Capacitors
C3_220µF 25V Electrolytic Capacitor
D1_LED Red 10mm. Ultra-bright (see Notes)
D2_1N5819 40V 1A Schottky-barrier Diode (see Notes)
Q1_BC547 45V 100mA NPN Transistor
IC1_7555 or TS555CN CMos Timer IC
L1_Sensor coil (see Notes)
B1_1.5V Battery (AA or AAA cell etc.)
Attachments
Last edited: