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Dear Swagatam,
I have been following your website as a hobbyist. i just want to make diy small washing machine about 3 to 4kg load with 12v or 230v ac. can you please advice me the motor and bi directional timer with pause
Thank you dear Prasad, I appreciate your interest very much.
It can be easily done using an IC 555 and IC 4017.
I will design it soon and let you know…
thank you Mr.swagatam. I will be happy to receive the same
No problem Prasad, you can try the following circuit
https://www.homemade-circuits.com/wp-content/uploads/2026/05/simple-washing-machine.jpg
can you please explain the diagram. And also substitute for transistors if any
Prasad, I have explained the full circuit in this post, please check it out:
https://www.homemade-circuits.com/make-this-simple-washing-machine/
Trying to use a LM2577-ADJ with 5v input from USB and to get 60v output.
I just cannot get any higher than 56.6v on my Fluke 77 multimeter, but my FNIRSI oscilloscope 1014D shows 59v. Not sure about that?
The R1/R2 ratio is set to R1=100k and R2=2.09k
Input cap = 100uF and output cap = 1000uF and inductor = 330uH
Schematic is based up https://www.ti.com/lit/ds/symlink/lm2577.pdf page 2. Tried different values for in and out elec caps, inductor and resistor ratio, and different diodes.
Any advice or have I just hit the limit on its output, with maybe an out-of-spec IC.
The output voltage you are seeing is quite normal for this configuration. Eventhough the resistor ratio correctly sets the output for 60V, yet boosting 5V up to 60V requires a very high duty cycle, close to the practical limit of the LM2577 IC.
Due to internal losses, switch saturation, diode drop, and efficiency limitations the IC typically cannot reach the exact theoretical value at such a high step-up ratio. So, an output around 56V to 58V is expected.
The difference between your multimeter and oscilloscope readings is also normal. The multimeter reads the average DC voltage while the oscilloscope displays peak voltage including ripple causing the higher reading on the scope.
Also if the circuit is powered from a USB source, then available input current may be limiting the output voltage further.
So in all your circuit appears to be functioning correctly and you are most likely observing the practical upper limit of the IC rather than a fault.
Many thanks Swagatam for a quick response.
I have come across similar problems with stated max values in datasheets, which is a bit misleading. This is something like 8% less than stated (theoretical value).
I will try a few changes to confirm practical limits.
1 – Revert back to the minimist component count and values.
2 – Check oscilloscope display settings for peak readings or whatever (V_pp, V_p, V_max, V_min,_avg, V_rms)
3 – Try using a more powerful 5v supply source.
Thank you Gray, for your understanding, sure, you can try those steps and let me know how it goes….please feel free too ask if you have any further doubts or questions..
Hi Swagatam – just an update
3 – tried using bench power supply for 5v supply with more Oomph, but that did not have any effect.
1&2 – In reverting back to original components. I removed 100uF across input, with just 0.2uF as smoothing on input. This had no effect.
This is where it gets interesting, as I removed all of the output smoothing capacitors (1000uF elec and 1uF ceramic).
In checking the output, I was somewhat surprised in getting the following waveform (sorry about file size) http://www.gb-online.co.uk/dump/LM2577-resized-20260504_103001.mp4
The Vpk is 95V dc coupled. The LM2577-ADJ was burning very hot, as it obviously did not like running above the 60v max with no output caps.
I should have put a 680uF across the output.
Got to wait for a replacement chip, and also change the 330uH for a 100uH
Hi Gray,
That waveform now explains the situation very clearly.
Once the output capacitors were removed, the boost converter output was no longer being filtered or averaged into a steady DC level. What you are now seeing on the oscilloscope are mainly the raw switching spikes and flyback energy pulses coming from the inductor, which is why the peak voltage is shooting up close to 95V.
Under this condition the LM2577 feedback loop also becomes unstable because it expects a reasonably smooth DC output for proper regulation. Without the output capacitor, the IC can momentarily overshoot far beyond the intended output voltage, causing excessive stress and heating of the internal switch transistor. So the overheating you observed is expected.
The output capacitor in a boost converter is actually a very critical part of the regulation system, not just a smoothing component. It stores the transferred energy between switching cycles and keeps the feedback loop stable.
A 680uF or 1000uF output capacitor should definitely be restored before further testing. Also, changing the inductor from 330uH to around 100uH may help improve the switching behavior for this application, especially at the high duty cycle required for stepping 5V up to 60V.
Hi Swagatam – We have reverted back to the Texas schematic with 100uH and output cap being 680uF but with the input cap only being 0.2uf (no elec cap).
Got the Vpk to be 59.5V and a ripple of about 600mV.
We did have to alter the R1 and R2 ratio as the resistors were way out of tolerance.
Going to next have a go at using LM358 + mosfet and multiple TIP32 for a 60V 30A power supply
So many thanks for listening to me.
Thank you Gray, for updating the results.
Sounds great! however LM358 + mosfet and multiple TIP32 looks like a linear regulator which will heat up a lot.
Instead why not design you own buck converter using the following tool:
https://www.homemade-circuits.com/buck-converter-calculator/
Is there a similar tool for Boost converter ?? Thanks
Yes, for boost converter you can try this tool:
https://www.homemade-circuits.com/ic-555-boost-converter-calculator/
Respected Sir,
I am interested in the circuit which track and remember the over and under voltage, the number of times it exceeds or goes low in 24 hours with memory.
I got totally confused with the products available on net/ amazon or other sites.
Please suggest something.
Mains over and under voltage tracking system
Hello Dhananjay, it is actually very easy.
You just need one LM393 IC and configure its one comparator to sense the high voltage, and configure the other comparator to sense the low voltage level.
Under both the conditions, the respective comparator outputs become high. These number of highs from the comparator outputs are fed to two separate digital counter circuits which display and record these ups and downs of the mains voltage.
You will need a battery backup for this circuit, to ensure the circuit memorizes the results even if the mains supply fails.
Respected Sir,
Thanks for your response and the valuable ideas.
Sir, since I don’t have sufficient time to get through the complex circuit and design the diagram, can you please share some assured readily available circuit boards in market.
Thank you Dhananjay, you can buy 4 separate modules, as given below.
1) 1no adjustable High voltage detector module.
2) 1no adjustable low voltage detector module.
3) 2nos digital counter circuits.
and now join these modules together as explained by me in the previous comment…
Hello Swag,
I kindly sent you a message on email and on facebook in case you didnt see it. But i think you blocked me, that is unfortunate. We genuinely needed your advice and help with our project.
I hope you understand that it is a legit request, and not spam.
Best
Rob (Bob Hein)
Hi Rob,
I never block any of my genuine readers.
I saw your email and have already replied to it.
Please check your email inbox…
All the best t you!
Sir swag, do you have any suggestion, on how to put an early warning device in a blind tunnel to avoid collision of two vehicles coming in two opposite direction?
the idea is to send signal to the other end of the tunnel not to enter the tunnel because there is someone already in the tunnel coming from the opposite direction…
the blind tunnel I was talking about is at least 500 o 700 meters long…there is no concern if the we’re riding on a motorcycle, the traffic can come from both directions… but for a 4-wheels, it’s a different stories, the tunnel turn into a one lane passageway….
Thanks Sir Swag, hoping you help us find a practical solutions, in favor of our community….
Thank you Cindy, for your interesting query.
I think that can be perhaps solved by installing vibration detectors on the railway tracks on both ends of the tunnel. If any one of the trains comes near the mouth of the tunnel, the indicator on the other end of the tunnel is activated, and vice versa happens when a train approaches the other mouth of the tunnel.
I hope it makes sense?
Yes Sir, that’s the idea…. but is it possible that both end of the tunnel well be aware of the actual location or distance of the vehicle moving inside the tunnel?….
can it be done with just a simple circuit….. and not a complicated one Sir?
Yes, I understand what you are trying to achieve, however, detecting actual location and distance can make the circuit quite complex. The vibration detection concept can be implemented very easily and effectively.
Hi Sir Swag, can you show me the circuit that detect vibration and guide me how the circuit works and it’s components…. thanks
Thanks Cindy, the vibration sensor will need to be installed inside the soils under the railway tracks, and the transmitter installed above the ground, on a pole for sending and receiving the signals….if possible I will try to do it soon…
thanks in advance Sir Swag, hoping that all the necessary components in your circuit are all available here in my location… can’t wait to build your circuit Sir🙂
Thanks Cindy,
You can start by building the following circuit first:
https://www.homemade-circuits.com/footsteps-detector-circuit/
If you succeed with the intended results then we can proceed with the integration of the transmitter section and receiver section.
hi Sir, just to clarify some component in the circuit:
IC3 in the circuit figures is IC 7555 but you mentioned it as IC 555, is it the same? also the loudspeaker is 70 ohms impedance, very rare value in my area Sir, common speaker available for us here are 2ohms, 4ohms, 8ohms only…or maybe i misunderstood everything Sir, please enlightened me, thanks
Hi Cindy, IC3 is 7555 which is the CMOS version of a standard 555 IC, meaning it can work with 3V also and with much lower currents. The speaker is not required, because we want to trigger a transmitter with the output, not a speaker…
If you are finding this circuit complex, you can try the following design instead:
https://www.homemade-circuits.com/sound-activated-led-lamp-circuit/
Hi Sir swag, any best possible replacement or equivalent for TL081 IC and OA90 DIODE, thanks
Hi Cindy, you can try TL071CP, LF351, OPA134PA…
or even uA741 might work…
Good morning Swagatam,
My name is Dorian, I am in need of some assistance with building two AC supply sources. I have a darkroom, I use an Omega Super Dichro enlarger. There are three different output voltages 120Vac, 6.3 Vac and 39.4 V ac. I would prefer the option to build two supplies that are variable to adjust for the 6.3 and 39.4. The transformer power supply, (Omega Chromacontrol) which includes the timer is severely arcing. I would like to have the transformer rebuilt, I can not find a source. I decided to take a different approach. I do not need the timer. I need to supply the enlarger head with the above mentioned voltages (measured at the supply). No where can I find schematics for building AC to AC. Just for information, I have a degree in Electrical Engineering, spent 30 years in avionics, I have lab experience. Much appreciated.
Good Morning Dorian,
Instead of trying to design an AC-to-AC electronic converter, I would recommend the simpler way to use two separate transformers, because that usually stays more reliable and there is less trouble later.
For Supply 1, which is for 6.3 Vac adjustable, we can use a transformer with 120 Vac on the primary side, then the secondary can be 6 Vac or 7.5 Vac, depending on what is available.
Power rating can be around 1 A and if the lamp current is not known higher, then this usually remains enough.
If exact 6.3 Vac is needed then we can add a small series resistor or maybe trim it a little through a variac, to bring it closer.
Now for Supply 2, which is 39.4 Vac adjustable, again primary stays 120 Vac but secondary can be 36 Vac with some trim adjustment, or directly 40 Vac if that type is available.
Power rating here depends fully on enlarger lamp current, so unless that current is known, then exact transformer size can not be fixed.
Since 39.4 Vac is not a common value, then easiest way is usually 36 Vac transformer with a small buck or boost trim winding.
Or we can use two secondaries, 24 Vac and 15 Vac and connect them in series.
That gives 24 + 15 = 39 Vac, so now it comes very near the required value.
Hello, I can’t do anything with the diagram, can you help me?Adjustable SMPS circuit 0-100 V 50 A
I will try to get a simpler design, if possible…
Hello from Italy, Swagatam!
For my motorbike I would need two circuits i’m unable to find anywhere… maybe I’m missing the right keywords, but right now I have no solution.
1) I would need a 12V stabilizer: i’ve put LED lamps on my bike, and also a DRL light, but they filckers a lot (the less power the bike uses -it has heated handgrip and seat- the more they flickers). So a Motorbike/Car 12V stabilizer, able to handle the power for two low/high beam LED lamps could be very useful.
2) on the Kawasaki of my son there’s such device, so his lamps go ON only when the engine is running, not just with the key switch.
Here’s the schematic: https://imgur.com/yQL2XCu
and here the detail: https://imgur.com/IF1vyWz
I don’t understand how it works, but I could use a relay that goes on only after the engine runs (maybe even delayed by a pair of second) so I could power some circuit not just by turning the key.
Thanks!
Hi Parduz,
for the stabilizer circuit I would recommend using a boost converter circuit such as the following one:
https://www.homemade-circuits.com/xl3608-5v-9v12v-dc-2-amp-boost-converter-module/
Make sure to put a large capacitor such as 6800uF/50V across the output terminals of the converter…
For the kawasaki bike, you can try adding the following relay circuit, and check how it works:
https://www.homemade-circuits.com/wp-content/uploads/2026/03/ignition-relay.jpg
Thanks.
About 2) I’ve drawed it in the Circuit Simulator:
https://imgur.com/a/P9bfG7e
Have I understood you well?
How can the relay retains itself once it switch on? To avoid fast switching if the engine have problem starting or chokes?
Your diagram is correct.
However, the relay will not remain latched in this diagram, if the engine stops or halts.
If you want the relay to remain latched, you will need to replace the BC547 transistor with an SCR C106.
BC547 base will replace with SCR gate, collector with anode, and emitter with cathode.
I previously found this power supply design on homemade-circuits.com.
I do not see it on the site any longer.
I do not remember the output specs.
I need something similar using the 2n3055 that will output up to 50vdc 10amp with overcurrent protection with led and audible warning.
Thanks for your interest, It is still there, here’s the article link:
https://www.homemade-circuits.com/0-to-50v-0-to10amp-variable-dual-power/
i need your help with 3000kw sinewave inverter here it’s failing
Please give more information…
Hi, Swagatam,
There are light sensing circuit and darkness sensing circuits using LDR all over the internet.
Is there a schematic on your site when both of them combined together?
Idea behind it is: when light level drops below predetermined level – LED comes on ( saying “Too dark”) , when light level gets above certain level – another LED comes on (saying “Too bright”). Levels could be adjusted with 2 different potentiometers, to have some hysteresis.
Do you ever come across such a schematic? It could be a good idea for your next tutorial.
Best regards, Michael
Hi Michael,
I think you can customize the circuit explained in the following article.
https://www.homemade-circuits.com/how-to-build-dual-solar-tracker-system/
You can eliminate the transistor bridge stage and connect the LEDs directly from the opamp output to ground with 1k series resistors…
Thank you, Swagatam,
I will look into the schematic. Want to have just one LDR and LM339 as a comparator.
https://www.homemade-circuits.com/how-to-make-ic-lm339-circuits/
Best regards, Michael
Yes, actually it can be designed using a single LDR and two comparators….let me know if you need any further help!!