The diagram demonstrates an extremely very simple voltage stabilizer design which are able to maintain massive output power approximately 5 to 10KVA. The application of SSR or solid state relays tends to make the output stage convenient to configure and very precise - thanks to the latest SSRs which are usually built to activate enormous power as a reaction to smaller input DC potentials.
The suggested circuit of a basic 5 KVA to 10 KVA automatic voltage stabilizer circuit is simple to recognize. All the opamps are organized in regular voltage comparator modes.
The presets P1 to P7 can be modified as per the needed tripping points, which is able to correspond to the output SSR switching and the successive transformer tap alternatives.
The central green TAP is the regular voltage output, the lower TAPs steadily generate much higher voltages while the upper TAPs are set for lower voltages.
These types of TAPs are selected by the suitable SSRs as a reaction to the varying AC voltages, thus modifying the output voltage to the appliances near to regular levels.

Parts List
- R1 to R9 = 1K, 1/4 watt,
- P1 to P7 = 10K preset,
- C1 = 1000uF/25V
- VR1 = 1K Preset,
- opamps = IC 324,
- Transformer = Input 230volts or 120volts, Taps - incrementing/decrementing voltage levels (TAPs) as per individual specs.
- SSR = 10KVA/230volts = output, 5 to 32 volts DC = input
this circuit is probably wrong. don’t build it unless you design/check it yourself. it might work if you redesign it 1. by connecting the mains input to the green 230 volt output so the various windings float on top of the 230 volts and add or subtract from it to provide the other voltages you need. note that you don’t need an isolated transformer and an autotransformer is smaller and cheaper. a separate winding for the 12 v would be a lot safer too so the op amp circuit is not floating at mains potential. or 2. the other option is to wind the transformer so there is 170 volts at the tap connected to ssr7 relative to the tap connected to ground. then the other taps going up in voltage from there. and connect ground and input neutral
Can you share the PCB Gerber File?
Sorry, I don’t have them with me….
सर इसमे प्रयोग की गई आईसी एवं एससीआर कौन से नम्बर के है बताने का कष्ट करे
IC LM324, 2 nos
Howdy,
I was wondering if you had a schematic and a parts list. For a automatic voltage stabilizer that the input power is 120 volts put it fluctuates up and down and I need it to stay at constant 120 volts.
Or if you had any other ideas what my work for this condition.
Hi, if you want perfectly stable output then perhaps you will need a PWM controlled circuit, which I do not have with me right now….
sir thanks very much for the circuit i ve been looking forward for this since. but my problem is i cant find the 0 volts on the secondary
asase, it is connected with C1 negative pin
Please, I wish to construct an automatic voltage stabilizer using a magnetic relay with 6 taps coil transformer. Kindly give a clue on how to go about it. Thanks in anticipation.
Replace the SSRs with opto couplers and connect the optocoupler outputs with relays
Kindly forward to me an automatic voltage stabilizer with 6 taps and the relay connection. Thanks in anticipation
Please admin,I have a project in school which is 3.5kw automatic voltage regulator with seven segments displays. How do I achieve that?
sorry Ayuba, I do not have a seven segment display circuit for this project!
Hi, 1-can you Explain how does it work?(electric explanation).
2-Is ground = neutral here?
3- in real transformer,secondary side, where should connect the capacitor???(positives are Taps and negative to a diod. And capacitor to…??
Hi, ground has no relation with the AC line, it indicates the DC negative live of the circuit.
In real transformer you will have separate two wires for the 12V supply, use those two wires for the diode and the capacitor connections as indicated in the diagram
What is the Z1 zener diode value?
6V will do!
IMHO green tap on secondary is supposed to be connected with Phase point and taps for reference supply must be isolated.
Pls check again….when you connect a load ; how circuit will work. There is no connection between transformer’s input and out put.
the transformer doesn’t have to be exactly as shown, forget about it…..just imagine a transformer having a phase 220v and neural taps, and many subsequent taps rated at 150v, 170v, 200v, 240v, 260v, 280v.
Now simply connect the phase 220v and neutral to mains input and the other taps as shown in the diagram, that’s all
At stabilized output neutral is ok but Phase connection is missing. Pls correct.
phase is coming from the relevant transformer taps. or it may be reversed also…
I have a 5kva century make 5relays stabilizer. The problem is when powered it displays a protection led light and does not supply output power. What is problem with it.
the protection circuit may be malfunctioning, remove this stage and check again, and then try troubleshooting this stage
Holle admin
circuit diagrame for 5kva stabilizer with digital display
I have the trasnformer wedding 7led
pls is my project at school
hello gbenga, for digital display you can integrate the following circuit
https://makingcircuits.com/blog/simple-digital-voltmeter-circuit/
Hello Admin,
Has any one loaded mfg’d and loaded the circuit to 5kVA?
The output circuit is not complete.
How can the secondary work with only one connection to output.
Hello Arun,
the output includes two connections, one is the common neutral and the other is from the respective taps of the transformer, stepped up or down through the SSR outputs
…if the trafo and the SSRs are rated at 5kva the output will be 5kva compatible.
Sir,Please, send me transformer 5kv/10kv input or output super cable size details
Helal, do you mean to say the winding detail?? sorry I do not have the winding detail for this…
Sir,Please, give me transformer tapping details
Helal, the taps are in the following sequence:
290,270, 250, 230, 210, 190, 170
230 is the central green tap
Sir
Please give me value of Z1
You can use a 6V zener
What would 10 or 12 KVA schematic would look like? Where would one get the tap transformer in a 12 KVA setup? Also, what would be the percentage of attenuation on spikes and brownouts. Thank You, Richard
The same schematic can be used for 10-12kva systems by suitably upgrading the transformer wattage and the SSRs…the spike, and brownout and related percentages have not been calculated…it will need to diagnosed with practical experimentation