Wiring Schematic Diagram

This is a signal injector circuit. Signal injector is important tool for troubleshooting your electronic circuits. As an example, this circuit can be used to test amplifier circuit. Here is the schematic diagram of the circuit:

This circuit also a lot of harmonics. By connecting the ground clip to the 0v rail and move through each stage, starting at the speaker, the fault in an amplifier can be found. At each preceding stage, the volume will increase. This circuit can inject FM sound sections in TV’s and the IF stages of radios.

When T1 conducts, its collector tension goes from high to low. Via C1, this is transmitted to the base of T2 making its collector tension drop from high to low as well. Via C2, this pulse blocks the base-current of T1, causing it to block up. As soon as the left side of C2 is charged enough by R3, T1 can conduct again and the cyclus is repeated.

This transformerless power supply circuit will of supply up to about 20mA at 12 volts. It uses capacitive reactance instead of resistance, and it does not generate very much heat.The circuit draws about 30mA AC. If you need more current, use a larger value capacitor, or put two in parallel, but be careful of what you are doing to the Watts. The low voltage 'AC' is supplied by ZD1 and ZD2. The bridge rectifier cans be any of the small 'Round', 'In-line', or 'DIL' types; or Could you use four separate diodes.

This power supply can not be modified to Provide currents of greater (can not be up to several amps). The circuit was Designed to Provide a cheap compact power supply for Cmos logic circuits require only A Few That milliamps. The logic circuits were the resource persons then Used to control mains equipment (fans, lights, heaters etc.) through an optically isolated triac. If More Than 20mA is required it is possible to increase of C1 to 0.68uF or 1uF and thus obtain a current of up to about 40mA. But 'suppressor type' capacitors are Relatively big and more expensive Than Regular capacitors; and Increasing the current That means higher wattage resistors and zener diodes are required. If you try to Produce More Than about 40mA the circuit will from no longer be cheap and compact, and it simply makes more sense to use a transformer.

C1             : 470nF/500V
C2             : 100µF/25V
R1             : anything from 1MΩ to 10MΩ
D1, D2, D3, D4 : 1N4007 or rectifier 230V AC
D5             : zenerdiode 12V or matching Uout desired

A very simple dimmer circuit with only the essentials. (In this circuit, the values are given for a BT138 at 220V AC, for 115V AC you may have to experiment with the values.)

R1 can vary from one triac to another, put a 220KΩ trimmer in its place and adjust. After adjustment, measure the result and replace the trimmer with an ordinary resistor of the same value.

This is simple 3-digits digital volt meter. The range is -99mV to +999mV. Two integrated circuits are used, the CA3161 and the CA3162.

IC1 converts the analogous signal to a digital signal and also produces the multiplex signal to drive T1-T3. The BCD-code from IC1 then goes to IC2, a BCD to 7-segment decoder/driver. From there the signal goes to the displays.

The timing for the CA3162 is supplied by a 786Hz ring oscillator, and the input at pin 6 determines the sampling rate. A 5V input provides a high speed sampling rate (96Hz), and grounding or floating pin 6 provides a low speed (4Hz) sampling rate. When pin 6 is fixed at +1.2V (by placing a 12K resistor between pin 6 and the +5V supply) a 'hold' feature is available. While the CA3162E is in the hold mode, sampling continues at 4Hz but the display data are latched to the last reading prior to the application of the 1.2V. Removal of the 1.2V restores continuous display changes. Note, however, that the sampling rate remains at 4Hz.

The 'EEE' or '---' displays indicate that the range of the system has been exceeded in the positive or negative direction, respectively. Negative voltages to -99mV are displayed with the minus sign in the MSD. The BCD code is 1010 for a negative overrange (---) and 1011 for a positive overrange (EEE).

To callibrate the circuit, connect HIGH and LOW to mass and adjust P1 to read '000'. Then connect a tension from 0 to 1V to HI and LOW with LOW connected to mass. Adjust P2 to read the tension in mV.

The measuring range can be raised, using tension dividers. To use the decimal points, connect DP1, DP2 and/or DP3 to mass.

This circuit is a digital frequency counter. It covers region 1HZ until 1MHZ. The IC1 schmitt trigger that it regulates the signal of entry and him changes in reasonable level suitable for the IC2-3-4. With the tenth pulse in the entry of IC2/1, is produced a pulse '' carry '' in the IC3/5. The same moment the IC2 causes the depiction in the display 1, The IC3 causes the display 2. When in the entry of IC3 it reaches and the tenth pulse, the display 2 and the display 3, (with total depiction 100, having the display in right order). The exit '' carry'' off IC4/5, can be used in order to it turns on the decimal point (comma) the display 1, in order to it shows a situation over the limits of measurement.

The timed begins with the one of half double timer (IC5A). Switch S1 select the interruption the time in 1sec or in 1ms. At the duration of this interruption, second half the (IC5B), it produces a interruption of depiction 2 or 3sec., at the duration which counter cut off by the entry and the displays remain OFF. In the end of depiction, a pulse RESET, begins the interruption of time/depiction.

The critical point is round the Q1-IC1, which should be placed as long as it becomes more near in the jack of entry, to reject of parasitic signals of high frequency. For the regulation, we can use a frequency counter good precision (if you do not have you are lented) and a generator of signal. We put switch S1, in place [HZ], we apply in the entry a low frequency and we regulate the trimmer TR2, so that we take the right clue, which should suit with source frequency counter We repeat also the regulation for the department of KHZ, with a higher frequency. The supply of circuit becomes with a battery +9V, if it is used as portable or from suitable power supply if it is incorporated in some unit that exists already.

List Component

R1     : 8.2Mohm          IC2-3-4 : 4026
R2-9   : 100Koh           IC5     : 556
R3     : 470Kohm          IC6     : 4007
R4     : 470 ohm          IC7     : 7805
R5-6-7 : 10Kohm           DS1-3   : Display 7segment Comm. Cath.
R8     : 3.3Mohm          TR1     : 1M ohm trimmer 
C1-2   : 1uF 63V Mylar    TR2     : 1Kohm trimmer 
C3     : 47uF 16V         Q1      : 2N930 
C4     : 100nF 63V        S1      : ON-OFF mini switch
C5     : 2.2uF 16V        S2      : 1X2 mini switch
C6     : 10uF 16V 
C7     : 10nF 63V Mylar
C8-10  : 1nF 63V Mylar 
C9     : 1uF 16V