Class D amplifier driven by 555 output

[darryl_co]

I'm not sure I know what a descaler is. Can you explain how it is susposed to work? I'm guessing it is a series resonant circuit with the inductor and capacitor?
I'll be back later.

An electronic descaler is a device that magnetizes water passing through the pipe using high frequency into a coil wound on the pipe.People using have claimed reduction in limescale produced in pipes and growth in produce of crops
This claims were made by end users I met personally

 

[alec_t]

An electronic descaler is a device that magnetizes water passing through the pipe using high frequency into a coil wound on the pipe.

Sorry, but the physics is wrong. You can't magnetise water. But the AC magnetic field from the coil might be useful to de-magnetise something ferromagnetic .

This claims were made by end users I met personally

People who have bought something naturally don't want to admit they've been conned. I'd be interested to know how they actually detected the reduction of scale. Did they scientifically, under controlled conditions, measure the scale quantity both before and after using the device?

 

[4pyros]

Sorry, but the physics is wrong. You can't magnetise water. But the AC magnetic field from the coil might be useful to de-magnetise something ferromagnetic

Alec; Its just one of those things like a magnetic bracelets conjured up to part us from our money.
https://en.wikipedia.org/wiki/Magnetic_water_treatment

 

[alec_t]

My sentiments exactly. But the OP presumably wants to try it regardless .

 

[darryl_co]

Sorry to disappoint you, alec_t and 4pyros.
I do not find any reason that any person who is known to you would not admit if he or she was conned and push you in the same hole that he has fallen into.He is not selling the product nor he is insisting I refer his name while purchasing or buy the same brand product.He very well knows that I would not buy one but make one for myself.He is ready to try it out for me any even buy if he gets the same result as the one made by me would be much cheaper.

Another experiment I have tried personally at a car wash using hard water with a Descaler unit.The car was washed with the unit turned off and water droplets were allowed to remain on the body and the glasses for 15 minutes than wiped off.There were water droplets stains on the body and glasses which got removed only after rewashing the car with the unit on.Even after 30 minutes the water could be wiped without leaving stains behind.

You could try this experiment by your self, If it works for you also great.If not think it to be a hoax and forget it, but I cannot.
The effect of a Descaler depends on the hardness and flow rate of the water.One particular unit will behave differently in different conditions.
Goodluck!

 

[alec_t]

The carwash experiment is unscientific and unconvincing because the condition of the car surfaces before the first wash is different from their condition before the second wash. You would need identical conditions for a valid comparison. I wish you luck if you go ahead with this project, but I won't be building one of these gizmos myself .

 

[darryl_co]

The carwash experiment is unscientific and unconvincing because the condition of the car surfaces before the first wash is different from their condition before the second wash. You would need identical conditions for a valid comparison. I wish you luck if you go ahead with this project, but I won't be building one of these gizmos myself .

To build one or not to build is totally your wish.The example given was to show that this was the problem faced by the car wash owner before installing the unit

 

[audioguru]

When I wash my car twice in a row then it is cleaner than when washed only one time.
Maybe the scum remaining is dirt, scale in the water or soap, or all of them.

I got it! The scum is diesel droppings from trucks and busses. They are oily soot that is hard to wash off.

 

[MrAl]

Hi,


The science behind this kind of device suggests that it is not a descaler, per se, but rather is an inhibitor, if it works that is. The science would probably have to be that of vibration, where it keeps the particles from interacting the way they normally do in a pipe type flow system where there is probably low turbulence, which brings us to another interesting idea (later).

It could work if done right because the stuff that travels through the pipe follows a certain kind of flow which is less toward the inside surface of the pipe and a sound wave could feasibly disrupt the regularized flow which could mean less gathering and less sticking.
A question that comes up is what is the best frequency, and what is the best or at least the minimum amplitude or power that needs to be fed to the pipe to inhibit the gathering and sticking?
Another question is will it work as well on horizontally mounted pipes as well as vertically mounted pipes?

It's hard to determine what the operating characteristics should be and how well it works in various applications.
For example, will it work in a small coffee pot like water heater of say 1 or 2 quarts capacity? This might not be too hard to test, but using devices made from different manufacturers would probably lead to different results.

Just to note, i've seen scaling 1/4 inch thick on the side walls of a pipe in an old house that was only about 5/8 inch inside diameter anyway, so the water flow was extremely restricted.


The solution might be to use a spread spectrum, but then the power for each frequency will be reduced, so the problem of how much power is required comes up again, and how much is this going to cost over the year? My guess is that it would have to use a lot of power to be effective over the whole length of the pipe, so it would cost quite a bit to operate.

 

[darryl_co]

The units I have seen state power consumption as 5 watts.I would say that higher the frequency higher the number of magnetic lines passing through the water per second.Its the difference between scraping a knife on a bunch of paper at one per second and 1000 times a second.Though the intensity of thousand times per second would be less, the paper would be more damaged than one time per second for a given time.
The right frequency can be found with trial and error
And for those who did not get the car wash experiment
Any car randomly selected and washed with the unit off produces water stains if not wiped quickly and any car again randomly selected (not the same car) does not leave back water stains when washed when the unit is on.
I dont think I can explain anything better than this.

 

[darryl_co]

I feel we have deviated from the purpose of this forum so please lets get back to it.
I would like an advice should I use 7400 or 4093 as inverter gates?
I want to use nand gate as I need an input to use as enable/disable pin so 7414 or 40106 is out of the question.

 

[ronv]

Use the CD40903. It will tolerate the 16 volt supply and interface with the 9 volt signal from the 555.

 

[alec_t]

Personally I'd use the 4093. Having a Schmitt input it's less prone to erratic triggering from slow pulse edges or electrical noise.

 

[darryl_co]

User ronv circuit has worked perfectly.I wanted to use a LED as an indicator which would light if the output coil is connected but cannot figure out how.Please guide

 

[ronv]

Add the LED and resistor as shown.

 

[darryl_co]

I was using the circuit provided by ronv but in long run the PNP transistor TIP127 connected to the positive line gets much hotter than the NPN transistor TIP122 connected to the negative line.The situation is the same as my three transistor circuit.The positive line transistor gets much hotter as compared to negative line transistor.Maybe both transistors remain on as the drive is a square wave so no dead time.The alternative to use is MOSFETs with a driver like IR2103 or NCP3420.
Which one is more advisable to use IR2103 or NCP3420?
Personal preference IR2103, reason easily available in local market.
I have a problem in wiring the IC.The illustration (IR2110)in the figure is confusing.
Vdd is Logic supply which in my case is 9v
Should I connect the Vcc pin and the Drain pin of the High side mosfet to 16V unregulated supply (12 VAC rectified and filtered)
Do I need the boostrap capacitor between pin 5 and 6
PS: The IRS2110 and 2103 are similar in connection except for the package 14pin & 8 pin, additional shutdown in 2110 and in 2103 same input can be fet to high and low input

 

[ronv]

Do you have the transistors on a heat sink? The top one dissipates almost a watt so it would be hot without one.

I like the 2103.

Vdd would need to be the 16 volt supply as it has an under-voltage lock out at 9 to 10 volts.

Yes, you need all the parts shown.

 

[darryl_co]

Do you have the transistors on a heat sink? The top one dissipates almost a watt so it would be hot without one.

I like the 2103.

Vdd would need to be the 16 volt supply as it has an under-voltage lock out at 9 to 10 volts.

Yes, you need all the parts shown.

Yes the transistors are on heat sinks.But when placed on individual heat sinks the upper transistors gets much hotter than the lower one indicating unbalanced conduction.

Vcc is the Low side and logic fixed supply voltage min -0.3V max 25V, so Vcc can be 9v.Please help with the component and Voltage values

 

[ronv]

Heat

The PNP transistor gets hotter because it is not as good as the NPN transistor.
The voltage drop from collector to emitter in the PNP at 2 amps is 1.2 volts while in the NPN iit is only .75 volts. So the PNP will be about 45% hotter.
Here are some values for the driver.

 

[darryl_co]

The PNP transistor gets hotter because it is not as good as the NPN transistor.
The voltage drop from collector to emitter in the PNP at 2 amps is 1.2 volts while in the NPN iit is only .75 volts. So the PNP will be about 45% hotter.
Here are some values for the driver.

In the three transistor amplifier the npn transistor connected to the plus line was getting much hotter than the pnp connected to the negative line.
Now as the pnp is connected to the plus line it gets hotter than the npn.So the point that the pnp is not good as the npn is not agreeable.
I do not understand why the positive rail connected transistor gets hotter.I even tried inverting the phase of the input signal.