Elecs-2.docx

CIRCUIT DESIGN

Figure 1: Circuit Design COMPONENTS Oscillator DC Supply R1 R2(Adjustable) R3,R4,R5 C1 C2 C3 C4 C5,C6,C7 Q1 Q2 Transformer

LM555 12V Battery 5kΩ 150kΩ 1.5kΩ 0.1uF 470uF 2.2mF 1000uF 600nF TIP42A (pnp) TIP41A (npn) Step-up

CIRCUIT DESCRIPTION The values of R1 and C1 were set as the reference in solving for R2 to get the duty cycle and output frequency of the oscillator, which is an astable multivibrator. To have a good output, the duty cycle needs to be approximately 50%. 𝑅1+𝑅2 𝑅1+2(𝑅2)

= 𝐷 ; 𝑅2 = 130𝑘Ω

The output of the oscillator alternates between high and low. 3 RC networks are connected to the output to convert the square wave into a sine wave. When the output of the oscillator is high the npn transistor is turned on and 12V is passed through 1

the transformer vice versa for the pnp transistor when the oscillator outputs a low the pnp transistor is turned on and the -12V voltage is passed through the other terminal of transformer giving an alternating effect of +12V and -12V. For an 8 ohm load the output power is : 𝑃𝑜 =

𝑉2 𝑅

=

2202 8

= 6050 𝑤𝑎𝑡𝑡𝑠

Figure 2: Output of the Oscillator A potentiometer is used in replacement for R2 to make sure the output is good. The frequency at which the oscillator operates is calculated by the formula : 𝑓=

1.44 (𝑅1+2(𝑅2))𝐶1

2

; 𝑓 ≈ 50𝐻𝑧

Figure 3: Output of the Inverter with an Oscilloscope

Figure 4: Output of the Inverter with a Voltage Probe

Names:

Francisco, Kayann B.

Aquino, Aldrin Paul C.

Deleon, Rikki Joshua M.

Lintag, Edgardo III R. Lopez, Aedrian M.

Section: BSECE-4A

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