Hero999

An SMPs can be made using fairly common components. The first shows how it can be done using diecrete components and the second shows a comparator. If a comparator with a push-pull output is used Q1, D1 R4 and R5 can be eliminated.

I mean anyone who says batteries are a higher quality voltage source than a linear regulator are talking rubbish. Some audiophiles believe all sorts of rubbish ranging from scratchy old valve amplifiers sounding better than solid state amplifiers to gold plated oxygen free mains cable being better than ordinary cable. There are idiots who will spend

Sorry buy that's total nonsense. A battery will have a much higher impedance than a linear regulator. A good amplifier will also have a high power supply rejection ratio so even if the power supply is noisy it won't make any difference. The only time when noise can be a problem is when it's at high frequency, above the bandwith of the amplifier which can cause noise on the audio due to non-linearities in the amplifier. High frequency noise is only a problem if a switching regulator is used and can be mitigated by adding a filter or a low drop-out linear regulator; when the latter is used, the configuration is often known as a hybrid regulator.

So you think more transistors must mean more distortion? Here's an example of a circuit which proves your theory to be wrong. In the first circuit there's three separate stages of voltage amplification, Q1 and Q2 just provide current amplification to drive R4, Q3 & Q4, Q6 & Q7, are Darlington pairs which have lots of gain, Q5 doesn't have much gain and just acts as an inverter. R5 to R7 help bias the transistors and provide negative feedback, C3 is a phase compensation capacitor which prevents oscillation. Notice how the output is a pretty clean and undistorted sinewave? In the second circuit, Q5 to Q7 have been removed so the closed loop gain is much lower. The cross-over distortion can be clearly seen on the output. This output stage is biased in class B which yields a low standby current but is very non-linear. The first circuit has a very high open loop gain and lots of negative feedback which dramatically reduces the distortion. The second circuit has a much lower open loop gain and much less negative feedback so the output remains very distorted. Paste the text between the code tags into a text editor, save with a .asc extension, open it using LTSpice and see for yourself. Version 4SHEET 1 880 680WIRE 272 -256 192 -256WIRE 416 -256 336 -256WIRE 192 -160 192 -256WIRE 192 -160 -176 -160WIRE 272 -160 192 -160WIRE 416 -160 416 -256WIRE 416 -160 352 -160WIRE 672 -160 416 -160WIRE 64 -80 -320 -80WIRE 208 -80 64 -80WIRE 464 -80 208 -80WIRE 592 -80 464 -80WIRE 464 -48 464 -80WIRE 64 -16 64 -80WIRE 208 -16 208 -80WIRE 592 16 592 -80WIRE -320 32 -320 -80WIRE 464 64 464 32WIRE 528 64 464 64WIRE -320 128 -320 112WIRE 592 176 592 112WIRE 672 176 672 -160WIRE 672 176 592 176WIRE 688 176 672 176WIRE 800 176 752 176WIRE 592 192 592 176WIRE 800 208 800 176WIRE 64 240 64 64WIRE 96 240 64 240WIRE 208 240 208 64WIRE 208 240 176 240WIRE 464 240 464 64WIRE 528 240 464 240WIRE 464 256 464 240WIRE 464 256 320 256WIRE 208 304 208 240WIRE 256 304 208 304WIRE 464 304 464 256WIRE 592 304 592 288WIRE 800 336 800 288WIRE 400 352 320 352WIRE 208 368 208 304WIRE 64 384 64 240WIRE 64 384 -80 384WIRE -496 400 -528 400WIRE -288 400 -432 400WIRE -176 400 -176 -160WIRE -176 400 -208 400WIRE 64 416 64 384WIRE 144 416 64 416WIRE 464 416 464 400WIRE -176 432 -176 400WIRE -144 432 -176 432WIRE 64 432 64 416WIRE -528 480 -528 400WIRE 0 480 -80 480WIRE -176 496 -176 432WIRE 64 560 64 528WIRE 208 560 208 464WIRE -528 576 -528 560WIRE -176 592 -176 576FLAG 464 416 0FLAG 592 304 0FLAG -320 128 0FLAG -528 576 0FLAG 800 336 0FLAG 208 560 0FLAG 64 560 0FLAG -176 592 0SYMBOL npn 528 16 R0SYMATTR InstName Q1SYMATTR Value BC547ASYMBOL pnp 528 288 M180WINDOW 0 60 32 Left 0WINDOW 3 59 68 Left 0SYMATTR InstName Q2SYMATTR Value BC557ASYMBOL Misc\\EuropeanResistor 448 -64 R0SYMATTR InstName R1SYMATTR Value 470RSYMBOL npn 400 304 R0SYMATTR InstName Q4SYMATTR Value BC547ASYMBOL voltage -320 16 R0WINDOW 123 0 0 Left 0WINDOW 39 0 0 Left 0SYMATTR InstName V1SYMATTR Value 10VSYMBOL cap -432 384 R90WINDOW 0 0 32 VBottom 0WINDOW 3 32 32 VTop 0SYMATTR InstName C1SYMATTR Value 220nSYMBOL voltage -528 464 R0WINDOW 123 0 0 Left 0WINDOW 39 0 0 Left 0SYMATTR InstName V2SYMATTR Value SINE(0 50mV 500)SYMBOL Misc\\EuropeanResistor 784 192 R0SYMATTR InstName R4SYMATTR Value 100RSYMBOL Misc\\EuropeanPolcap 688 192 R270WINDOW 0 32 32 VTop 0WINDOW 3 0 32 VBottom 0SYMATTR InstName C2SYMATTR Value 100

1) It shouldn't be. 2) That depends on the power supply, a regulated power supply is much better than a battery.

The Art of Electronics is still a good book, believe it or not the basic principles haven't changed in the last 20 years.

I'd recommend using a 1.5A transformer in a 1A regulator circuit. The next question will probably be: "I've built the circuit using a 6VAC adaptor but the output voltage drops when a 1A load is connected. What's wrong?"

Let me guess, it's a set of Christmas tree lights? Any TO-92 SCR with an adequate voltage rating will probably do but be careful with the pin-out. It might be a good idea to check the pin-out for the one that works before getting a replacement. I have some old Christmas tree lights I'm throwing way. I ripped open the controller and found four XL1225 SCRs which I'll desolder and test. The controller IC is marked SU168 which could be anything. It's a typical example of shoddy cheap Chinese construction and looks like a five year old put it together which is probably true.

Sorry but if you need to ask this then you probably need to do some more learning before you build your own regulator circuit. I suggest doing a bit more research.

Sorry, your post doesn't make any sense. Please tell us exactly what you are trying to do?

No one's going to design the whole thing for you. I'll give you an idea as to the basic building blocks and you can go away and research them. A pure sinewave inverter has three main components: a sinwave gennerator, DC-DC converter and a class D amplier. The 12VDC is boosted to just above the peak voltage of the AC output which is in this case 220√2 = 311V so the DC bus should be around 320V to 350V. A class D amplifier is connected to the DC bus. The input to the class D amplifier is connected to a very stable sine wave oscillator. A class D amplifier uses high frequency PWM and a low pass filter and is much more efficient than a normal audio amplifier which is why it is used. Research the following for more information: PWM (Pulse Width Modulation). h-bridge. Class D amplifer. DC-DC converter. Sine wave oscillator. Please don't ask any more questions until you've thouroughly researched the above.

It's an autotransformer. It has three connections, primary, secondary and neutral. Both the neutral for the input and output connect to the neutral. http://en.wikipedia.org/wiki/Autotransformer The only trouble is you need to identify the different windings. My guess is that the middle is the secondary tap. You can confirm this using a DVM, the primary will have a higher resistance than the secondary.

Does the radio have an AUX input? If so connect it to that, you can safely connect the left and right channels together. As audioguru said connecting outputs together is a recipe for disaster.

Take it you mean 30kWh per day? That's an average of 1.25kW. Firstly you need to cut down on the electricity usage as much as possible. Have you done the following? Replaced all heating appliances with gas. Installed smart master/slave sockets to cut down the number of devices on standby. Replaced all incandescent lamps with compact fluorescents and LEDs. What's your peak power usage? The inverter needs to be powerful enough to handle it, You can directly wire the lighting to the DC battery (you can buy DC compact fluorescent lamps) which will reduce the required inverter size and save power because there'll be less losses.

Bubble memory? Does that thing use valves (tubes)?

It is possible to do that but we can't do it, only the administrator can.

Here's a cheaper meter. It's probably not very accurate so will need calibrating. http://www.maplin.co.uk/Module.aspx?ModuleNo=5635

It's actually pretty simple. He already knows the heat input. All he needs to do is calculate the power output which is as simple as connecting a resistor, measuring the voltage and current, and applying Ohm's law. Then he'll have the power in and power out, enabling him to calculate the efficiency. If this is a college project, he could look at the hot and cold temperatures, calculate the efficiency of an ideal Carnot heat engine and see how his thermoelectric heat engine measures up to it.

The normal way to do this is to use a transformer but you might be able to use a cheaper and more compact method depending on what you're doing. I agree with the others: your diagram doesn't make much sense and needs more detail.

It's not cheap though, you could buy a decent DVM for less than that. A 1Ω resistor would also dissipate 100W at the full range of 10A. You're better off using a 50

Look it up on Wikipedia: http://en.wikipedia.org/wiki/Ameter This is more of a mechanical project than electrical. Care to mention the current range? You might need a shunt resistor in parallel with the coil but that's about it.

That's right, you got there in the end.

That's pretty far out. What value did you calculate? Look at the datasheet for a comparator IC such as the LM393, do you really think it can directly control a motor? Yes.

We've already told you, perhaps Mr Caps Lock will make it more clear: NO IT IS NOT POSSIBLE TO USE AN INFRA-RED RECEIVER AS A TEMPERATURE SENSOR.

Stupid question, how can it measure temperature, it's a microphone? Don't be silly, it measures sound not temperature.