Wiring & diagram Info: Frequency

Showing posts with label Frequency. Show all posts

Wednesday, November 19, 2014

Radio Frequency Generator Schematic

Radio Frequency Generator (RFG) is a tool used to generate the RF frequency. In the experimental modulation technique Radio Frequency Generator (RFG) is used as a carrier signal generator (carrier). The series of Radio Frequency Generator (RFG) can generate frequencies from 150KHz - 12 MHz. The series of Radio Frequency Generator (RFG) has been equipped generator modulation signal (information signal) that can be used to adjust the position of switch SW2. The series of Radio Frequency Generator (RFG) is also equipped with output level control via potensio VR1 and the output impedance selector selector with SW1. The series of Radio Frequency Generator (RFG) is also equipped with selector selector frequency band consisting of 5 range. For more details can be seen from the picture series of Radio Frequency Generator (RFG) follows.

The series of Radio Frequency Generator (RFG) above has 5 frequency range 150 KHz - 500 KHz, 350 KHz - 1 MHz, 750 KHz - 2.25 MHz, 1.6 MHz - 5 MHz and 3.5 MHz - 12 MHz. Selection of frequency range tersbut done by adjusting the position of selector switch SW3. To adjust the working frequency Radio Frequency Generator (RFG) is done by adjusting the lever variable capacitor (Varco), C1 and C2 are connected parallel.

Wednesday, October 15, 2014

Simple Discrete Sliding Tone Frequency Ramp Doorbell

This Discrete Sliding Tone (Frequency Ramp) Doorbell circuit produces a low tone that will slide up to higher frequency. The equivalent total resistance connected between the base of Q1 and ground (Rbg) , and coupling capacitor C1 determines the AF oscillator’s frequency. The resistance (Rbg) is equal to (R2+R1)R3.

Here is the schematic diagram of the circuit. The R2 is used to set the initial bias condition, adjusted to produce a pleasant low starting frequency doorbell tone. D1 will start to conduct when Capacitor C3 charge through R6 until it reaches D1 bias voltage level.

Then the value of Rbg is paralleled by R4 and D1, and R5-D2-D3, and the values of diode’s equivalent resistance is gradually decreased as the C3 voltage ramp up. This decreasing resistance value make the output tone slides up in frequency. Two different diode path is provided to extend the linear area of diode conduction transition slope. With two path with different biases, after the single diode path has saturated, the second path provide further linear increase at higher voltage level.

Discrete Sliding Tone (Frequency Ramp) Doorbell Circuit