Schematic Invert1: Basic Inverter circuitry w/ buffer amplifier.
Transistors Q3 and Q4 make up the buffer amp section.
**NOTE** This drawing demonstrates very simple and basic circuitry for a DC to AC Inverter using no IC's. Only uses basic components.



This schematic shows a basic and simple Inverter with the frequency clock circuitry [for timing the transistors at 60Hz].
Frequency can be decreased by increasing the sizes of C1 and C2. For higher Hz, decrease the sizes of C1 and C2.



Schematic of a Saturable-Core Inverter
[found this one in a transformer design book]



Spikes can be reduced by Capacitors C1 and C2
[also from transformer design book]



A small bias on the bases of Q1 and Q2 via R1 and R2, assists in "starting" This gives each transistor's base a small forward bias, so that both transistors tend to conduct when the circuit is first switched on [the base voltage on each transistor is zero when circuit is first switched on, so the small forward biasing thru R1 and R2 results in an above zero voltage at each base].

These schematics cover simple Inverter circuitry in 5 separate sections. The transistors would be Bipolar here.
Use of IC timing [clock] circuitry, along with quality core materials for the transformers and possibly JFET's wil increase the accuracy, and decrease the losses, making the Inverter more efficient. The transformers' coils and cores will need to be large, since the output Hz required is 60Hz. If this was part of a DC to DC converter, or if this was used for Frequency Inversion [input = low Hz, output = High Hz], then the clock circuitry can be set for a higher Hz... like 40KHz [or what ever the output Hz will be]. Being up in that range will reduce the size of the transformers dramatically - which also increases efficiency by decreasing core losses, winding losses and losses from heat [winding resistance, core's reluctance, etc.].

Discussion for these schematics can be found in the Theory area.
Look under the topic:
Discussion Thread for: inverter schematics
Feel free to post any and all comments or questions you might have in that thread.

Scott SET posted 09/07/2001