Generator of Functions
Either we have studied the operation of a typical oscillating generator or, and saw but the common ones, reason why or we can to be able to realize the selection and design of all the parts compose that them.
In order to obtain a perfect compensation thermal, he is deductible that we will decide on the use of an integrated circuit before discreet elements.
In addition, type of waveform of exit interests to us to have three at least (sine, triangular and squared), consequently we will be able to decide on integrated circuit ICL 8038 of Intersil, since it fulfills these conditions, being able to generate these waveform in an ample rank of frequencies.
Said integrated he is able to produce to those signals with high accuracy and also it can generate pulses of variable width with a minimum of external components. The oscillation frequency can vary between 0.001 Hertz and 300 KHz.
The scheme of our generator of functions will be the following one:
Power supply of the generator of functions
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List of components |
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| Resistance and potentiometers: | Capacitores: | Semiconductors: | Several: |
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- R1 - 1 K 1/4 W - R2, R8 - 33 K 1/4 W - R3, R4 - 6.8 K 1/4 W - R5, R6, R21, R22, R26, R27 - 10 K 1/4 W - R7 - 100 K 1/4 W - R9 - 22 K 1/4 W - R10, R15, R19, R20, R23 - 47 K 1/4 W - R11, R25 - 15 K 1/4 W - R12 - 12 K 1/4 W - R13, R14 - 100 K 1/4 W - R16 - 18 K 1/4 W - R17 - 1.8 K 1/4 W - R18 - 200 1/4 W - R24 - 47 1/4 W - P1 - 10 K (panel) - P2 - 1 k (panel) - P3, P4 - 100 k (printed circuit) - P5 - 47 k (panel) - P6 - 10 k (printed circuit) |
Ceramic or of polyester: - C1 - 479 pF, 10% - C2 - 4.7 nF 10% - C3 - 47 nF 10% - C4 - 470 nF 10% - C6, C7, C9, C10, C14, C15 - 100 nF - C8, C11 - 10 pF Electrolytic: - C5 - 4.7 uF, 35 V, 10% tantalum - C12, C13 - 470 uF, 35 V, aluminum - C16, C17 - 10 uF, 25 V, aluminum - C18 - 100 uF, 40 V, aluminum |
- D1, D2, D3, D4, D7, D8 - Diodes 1N4001 - D5, D6 - Diodes 1N914 - T1 - Transistor 2N4392 or equivalent - CI-1 - ICL8038 - CI-2 - TL082 - CI-3 - L7815AC - CI-4 - L7915AC |
- I1 - Commutator, 1 circuit 5 positions, printed circuit. - I2, I3 - Commutator, 1 circuit 3 positions, printed circuit. - TR1 - Transformer 220 V/15 V, 200 mA. - F - Fuseholder and 0.5 fuse of A. - P - Pilot 220 V, neon. - 1 Switch - 6 bellboys of control. |
Function of the commutators and potentiometers:
In P1 the adjustment of frequency is realized and with the I1 commutator the selection of the suitable scale.
I1 has its passages in relation 10:1, and as the frequency and the value of the capacitor have a linear relation, if the frequency diminishes 10 times, the capacity will increase in a relation 10.
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Step |
Frequency | Capacitor |
| 1 | 1 - 10 Hertz | 4,7 uF |
| 2 | 10 - 100 Hertz | 470 nF |
| 3 | 100 - 1,000 Hertz | 47 nF |
| 4 | 1 - 10 KHz | 4,7 nF |
| 5 | 10 - 100 KHz | 470 pF |
The symmetry adjustment takes control of P2 and the one of distortion of the sine wave with P3 and P4, being used one for each half-cycle, these potentiometers are the recommended ones by the manufacturer.
The function of the I2 commutator will be the one of selection of the type of exit wave.
In I3 the amplitude of the exit is selected (5 V, 500 mV or 50 mV)
With P5 the exit amplitude is regulated linearly and with P6 the level of continuous adjusts (“offset”), whose value varies between - 5V and + 5V
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