Inside Circuits

The circuit utilizes CA3160 and CA3140 BiMOS op amps to provide a full-scale meter deflection of ± 3 pA. The CA3140 serves as an 1T0 gain stage to provide the required plus and minus output swing for the meter and feedback network. ..

Views: 2008 | Votes: 42 | Comments: 0 | Rating: 6 | Rank: 4 | Added: Mar 23, 2013 |

Dc power can also be controlled via fiberoptics. The circuit provides an insulated speed control path for a small dc actuator motor (< Vn hp). Control logic is a self-contained module requiring about 300 mW at 12 V, which can be battery powered. The control module furnishes infrared pulses, at a rate of 160 Hz, with a duty cycle determined by the position of the speed adjust potentiometer. The programmable unijunction multivibrator provides approximately 10 mA pulses to.....

Views: 4642 | Votes: 12 | Comments: 0 | Rating: 3 | Rank: 5 | Added: Mar 23, 2013 |

Tone control of audio systems involves altering the flat response in order to attain more low frequencies or more high ones, dependent upon listener preference...

Views: 1086 | Votes: 108 | Comments: 0 | Rating: 2 | Rank: 4 | Added: Mar 23, 2013 |

For positive protection of electrical or electronic equipment, use this against excessive supply voltage. Due to improper switching, wiring, short circuits, or failure of regulators, an electronic crowbar circuit can quickly place a short circuit across the power lines, thereby dropping the voltage across the protected device to near zero and blowing a fuse. The triac and SBS are both bilateral devices, the circuit is equally useful on ac or dc supply lines. With the.....

Views: 1080 | Votes: 3 | Comments: 0 | Rating: 1 | Rank: 5 | Added: Mar 23, 2013 |

The circuit will provide 3 preset currents which will remain constant despite variations of ambient temperature or line voltage. ZDl produces-a temperature stable reference voltage which is applied to the noninverting input of ICl. 100% feedback is applied from the output to the inverting input holding the voltage at Q2s emitter at the same potential as the noninverting input. The current flowing into the load therefore is defined solely by the resistor selected by Si..

Views: 5383 | Votes: 50 | Comments: 0 | Rating: 3 | Rank: 5 | Added: Mar 23, 2013 |

For frequencies below 20 MHz, a fundamental-frequency crystal can be used and the resonant tank is no longer required. Also, at this lower frequency range the typical MECL 10,000 propagation delay of 2 ns becomes small compared to the period of oscillation, and it becomes necessary to use a noninverting output. Thus, the MC10116 oscillator section functions simply as an amplifier. The 1.0 Kohm resistor biases the line receiver near "BB and the 0.1-uF capacitor is a.....

Views: 6 | Votes: 78 | Comments: 0 | Rating: 6 | Rank: 5 | Added: Mar 23, 2013 |

Each time the switch closes, the voltage on Cl causes inverter A to change state, with positive feedback from inverter B. Resistor Rl delays the charging and discharging of Cl, making the circuit virtually immune to contact bounce. The circuit works with either CMOS or TTL gates. The values of R1 and C1 are not critical and can be increased for greater contact bounce protection, if needed. ..

Views: 7 | Votes: 57 | Comments: 0 | Rating: 7 | Rank: 5 | Added: Mar 23, 2013 |

This unit uses switches and resistors to provide a number of current ranges. It allows you to test most of the meters availabl..

Views: 5 | Votes: 41 | Comments: 0 | Rating: 5 | Rank: 5 | Added: Mar 23, 2013 |

Built arouud Precision Monolithics Inc. OP-50 op amps, this amplifier will drive 100- to 14 headphone, is flat within 0.4 dB from 10 Hz to 20 kHz, and has a THD of less than 0.01% over most of the audio range. ..

Views: 13 | Votes: 91 | Comments: 0 | Rating: 9 | Rank: 5 | Added: Mar 23, 2013 |

This circuit delivers 10 kV peak, then limits current to 7.5 mA @ 2 kV. The resistors shown provide ballasting. ..

Views: 10 | Votes: 93 | Comments: 0 | Rating: 3 | Rank: 5 | Added: Mar 23, 2013 |

A silicon-controlled rectifier is installed in parallel with the 12-V line and connected to a normally-closed 12-V relay, K1. The SCR's gate circuit is used to sample the applied voltage. As long as the applied voltage stays below a given value, SCR1 remains off and Kl's contacts remain closed, thereby supplying power to the load. When the source voltage rises above 12 V, sufficient current is applied to the gate of SCR1 to trigger it into conduction...

Views: 4084 | Votes: 67 | Comments: 0 | Rating: 9 | Rank: 6 | Added: Mar 22, 2013 |

Ql and Q2 form a constant current drive defined by R2. (I approximates to the reciprocal of R2 in the circuit shown for values of I greater than 1 amp). The pulse current is drawn from Cl which is recharged during the time between pulses via Rl. ..

Views: 2927 | Votes: 81 | Comments: 0 | Rating: 3 | Rank: 4 | Added: Mar 22, 2013 |

This circuit uses a 74S00 Schottky TTL gate..

Views: 2666 | Votes: 69 | Comments: 0 | Rating: 0 | Rank: 5 | Added: Mar 22, 2013 |

This circuit has a 100 mV hysteresis which can be used in applications where very fast transition times are required at the output even though the signal is very slow. The hysteresis loop also reduces false triggering due to noise on the input..

Views: 5192 | Votes: 5 | Comments: 0 | Rating: 4 | Rank: 5 | Added: Mar 22, 2013 |

The test circuit gives an indication of the capacity remaining in a battery. By noting the time in seconds that the LED remains on after you depress the test switch Sl. The circuit has proven reliable in testing NiCad-, carbon-, and alkaline-type batteries. Closing Sl activates the circuit by applying voltage from the battery under test. ..

Views: 9 | Votes: 52 | Comments: 0 | Rating: 2 | Rank: 5 | Added: Mar 22, 2013 |

A cascode amplifier using two MOSFETs is shown in the diagram. L2C1 and L3C2 resonate to the frequency in use. The cir..

Views: 14 | Votes: 73 | Comments: 0 | Rating: 9 | Rank: 5 | Added: Mar 22, 2013 |

The automobile delayed kill switch is simple in concept. When you get out of your car, a secretly located pushbutton switch is pressed. Nothing apparently happens, but at the end of a predetermined time, a relay is pulled in and locked. When the relay is pulled in, contacts open, and the hot lead from the ignition to the coil and the hot wire from the key switch to the starter solenoid is opened or disconnected. If the engine is running, ..

Views: 10 | Votes: 28 | Comments: 0 | Rating: 6 | Rank: 5 | Added: Mar 22, 2013 |

This modem/fax protector can be used in telephone-line connections between a PC or a terminal and a distant computer. In this circuit, the SVPs (surge voltage protectors) are rated at 230 V...

Views: 0 | Votes: 98 | Comments: 0 | Rating: 3 | Rank: 5 | Added: Mar 22, 2013 |

You need free power? This schematic transforms the surrounding radio waves to usable current. The levels of power can be stepped up by using more diodes. The critical points in this device are first the type of diodes and second the antenna construction. The more diodes the more power out! And guess what, no ground needed....

Views: 659 | Votes: 37 | Comments: 0 | Rating: 5 | Rank: 10 | Added: Mar 21, 2013 |

An RF input is applied to the primary of Tl, which applies equal amplitude, opposite phase RF drive for output FETs Ql and Q2. With no AF modulation at points A and B, the opposite phase RF signals cancel each other and no output appears at the 50 V output connector. When AF modulation is applied to points A and B, a modulated RF output is obtained. The dc stability and low frequency gain are improved by source resistors R18 and R19...

Views: 1642 | Votes: 76 | Comments: 0 | Rating: 3 | Rank: 3 | Added: Mar 21, 2013 |