Electronics Handbook/Devices/Amplifier/DC Volatge Amplifier

Transformer Amplifier

 * Single-phase_transformer.svg


 * $$\frac{V_s}{V_p} = \frac{N_s}{N_p}$$
 * Transformer acts as Amplifier if N2 > N2

Transistor Amplifier
When Transistor conducts current
 * Ib ≠ 0, Ie = α Ib , Ic = β Ib

Inverting Amplifier

 * $$\frac{V_o}{V_i} = 1 - \frac{R_2}{R_2 + R_1} \frac{R_3}{R_4}$$

When R1
 * $$\frac{V_o}{V_i} = 1 - \frac{R_3}{R_4}$$
 * $$\frac{V_o}{V_i} = -n$$ provided that R3 = (n+1)R4

Non Inverting Amplifier

 * $$\frac{V_o}{V_i} = \frac{R_2}{R_2 + R_1} \frac{R_3}{R_4}$$

When R1
 * $$\frac{V_o}{V_i} = \frac{R_3}{R_4}$$
 * $$\frac{V_o}{V_i} = n$$ provided that R3 = nR4

Inverting amplifier

 * [[Image:Opampinverting.svg|250px|Inverting amplifier]]
 * $$ V_\mathrm{out} = - V_\mathrm{in} \left( {R_f \over R_1} \right)$$

Non-inverting amplifier

 * [[Image:Opampnoninverting.svg|250px|Non-inverting amplifier]]
 * $$ V_\mathrm{out} = V_\mathrm{in} \left( 1 + {R_2 \over R_1} \right)$$