Dc to ac inverter circuit debug please

AI Thread Summary
An electrical engineering student is troubleshooting a 12V to 120VAC inverter for a capstone project, achieving 59Hz output until it reaches the transformer, where the frequency spikes to 177Hz. Participants in the discussion suggest posting a schematic and measuring waveforms to better diagnose the issue. Concerns about safety and the importance of having a faculty advisor are raised. The presence of third harmonic distortion in the output signal is noted, with advice to add a resistive load to potentially stabilize the frequency. The discussion emphasizes the need for careful debugging to ensure proper functionality of the inverter circuit.
tomos976
Messages
2
Reaction score
0
Hello I am a EE student and was wondering if anyone had some suggestions on how to fix my inverter it's for a capstone project we are using a twelve volt battery and trying to get 120vac 60Hzs we can get 59Hzs from the curcuit intill it goes into the transformer then it changes to 177Hzs and ideas. and yes i am well aware of the dangers we need just enough amps and watts to run a light bulb. thank you
 
Engineering news on Phys.org
tomos976 said:
Hello I am a EE student and was wondering if anyone had some suggestions on how to fix my inverter it's for a capstone project we are using a twelve volt battery and trying to get 120vac 60Hzs we can get 59Hzs from the curcuit intill it goes into the transformer then it changes to 177Hzs and ideas. and yes i am well aware of the dangers we need just enough amps and watts to run a light bulb. thank you

Welcome to the PF.

Well, the power to run a 120Vrms lightbulb can be plenty dangerous. Do you have a faculty advisor who is overseeing this project?

Can you post a schematic of your circuit and system? We will probably need to see that to be of any help.
 
dc to ac inverter debug

I'm building a 12v inverter. I can get 60Hzs on the circuit in-till it goes through the transformer it changes to 177Hzs does anybody have any ideas here is the circuit I'm using

C1, C2 2 68 uf, 25 V Tantalum Capacitor
R1, R2 2 10 Ohm, 5 Watt Resistor
R3, R4 2 180 Ohm, 1 Watt Resistor
D1, D2 2 HEP 154 Silicon Diode
Q1, Q2 2 2N3055 NPN Transistor (see "Notes")
T1 1 24V, Center Tapped Transformer
 

Attachments

  • pf inverter.gif
    pf inverter.gif
    2.5 KB · Views: 650


tomos976 said:
I'm building a 12v inverter. I can get 60Hzs on the circuit in-till it goes through the transformer it changes to 177Hzs does anybody have any ideas here is the circuit I'm using

C1, C2 2 68 uf, 25 V Tantalum Capacitor
R1, R2 2 10 Ohm, 5 Watt Resistor
R3, R4 2 180 Ohm, 1 Watt Resistor
D1, D2 2 HEP 154 Silicon Diode
Q1, Q2 2 2N3055 NPN Transistor (see "Notes")
T1 1 24V, Center Tapped Transformer

How are you measuring the waveforms on primary and secondary? Can you post screenshots of the waveforms?
 


tomos976 said:
I'm building a 12v inverter. I can get 60Hzs on the circuit in-till it goes through the transformer it changes to 177Hzs does anybody have any ideas here is the circuit I'm using

C1, C2 2 68 uf, 25 V Tantalum Capacitor
R1, R2 2 10 Ohm, 5 Watt Resistor
R3, R4 2 180 Ohm, 1 Watt Resistor
D1, D2 2 HEP 154 Silicon Diode
Q1, Q2 2 2N3055 NPN Transistor (see "Notes")
T1 1 24V, Center Tapped Transformer

There's a lot of third harmonic in a square wave. It sounds like you're getting a peaky 3rd harmonic response out of that transformer. If you're testing it open circuit then try adding some resistive load (like your light bulb) and see if that dampens it.
 
Thread 'Weird near-field phenomenon I get in my EM simulation'
I recently made a basic simulation of wire antennas and I am not sure if the near field in my simulation is modeled correctly. One of the things that worry me is the fact that sometimes I see in my simulation "movements" in the near field that seems to be faster than the speed of wave propagation I defined (the speed of light in the simulation). Specifically I see "nodes" of low amplitude in the E field that are quickly "emitted" from the antenna and then slow down as they approach the far...
Hello dear reader, a brief introduction: Some 4 years ago someone started developing health related issues, apparently due to exposure to RF & ELF related frequencies and/or fields (Magnetic). This is currently becoming known as EHS. (Electromagnetic hypersensitivity is a claimed sensitivity to electromagnetic fields, to which adverse symptoms are attributed.) She experiences a deep burning sensation throughout her entire body, leaving her in pain and exhausted after a pulse has occurred...
Back
Top