Function Generator

Dr. Fotowat & Dr. Kavehvash

Prepared by Mostafa Hosseini

Fine Frequency Adjust

Function Wave-Form Select

Course Frequency Range

Amplitude Adjust

DC Offset Adjust

Output Port

TTL Output Port

Output Voltage Range

Pulse to Triangular Voltage Circuit:

Pulse to Triangular Voltage :

Current Source

Simple Circuit (pulse to triangular):

Too simple circuit (pulse to triangular):

Input : H ------> output increaseInput : L------> output decrease

Buffer (FET):

Buffer circuit :

• Infinite impedance• Zero-DC shift

Amplifier:

Push-Pull Circuit

Frequency Range Circuit:

Frequency Range Circuit:

Triangular to Sin Voltage Circuit :

Triangular to Sin Voltage Circuit :

When amplitude of triangular voltage increase--->first D112:on --->R=R159+R166By increasing amplitude--->D111:on --->R=[(R158+R165)||R159]+R166...

As you see, gain decrease and our triangular voltage has been converted to sin voltage.

Simple simulation:

Simple Circuit (Triangular to Sin Voltage) :

By Changing Gain(when input increase, gain decrease)We Can Convert Triangular to Sin Voltage.

• Function Generator generate pulse, sin and triangular voltage continuously …

Choose a Wave-Form Amplifier

Choose output range 10dB,20dB,40dB

Circuit of Wave-Form Select :

Circuit of Wave-Form Select :

Output Amplifier:

Output Amplifier:

Darlington Push-Pull Circuit

Circuit of output range (10dB,20dB,40dB) :

Circuit of output range (10dB,20dB,40dB) :

Output

• Function Generator needs DC voltage for biasing. So we should provide DC voltage by Regulator. We use MC7815 and MC7805 to provide -15V & -5V. Also for +15V and +5V, MC7915 and MC7905 has been used.

• The blow circuit has been designed for providing +10V & -10V.

+10V & -10V DC Voltage Circuit :