Ldanielrosa

I am not an audio enthusiast. That much said, I think I have seen a lot of things that use 5532 because of availability. The THD of this device will be negligible compared to any other item in the system, unless you are using $600 headphones.

I won't say should. If you have experience with them you will already know the advantages. If not, then this project alone would not justify the costs involved with starting microcontrollers. I can't recommend using two computer supplies in series. Some require a load on the 5V section. Many have less than stellar regulation on the 12 part.

Is the transformer center tapped?

This is going far, so I will say this. If someone does find a way to get unlimited free energy, I hope they destroy it along with all the evidence. If such a source became available it would be abused in short order _WITH ABSOLUTELY NO EXCEPTIONS_. We would incinerate ourselves.

Are you using a microcontroller?

If it was the electrician's fault, then absolutely blame him. If he did make modifications (which perhaps should have worked), then he should have notified you &/| left an as-built. AC or DC, 12V or 120V, it's his job to know what he's doing and when he's outside his realm of training. Would you expect a motocross racer to operate a tractor? Would you have a jetski fanatic pilot a helicopter? BTW, I'm trying to join the guild and I will expect competence from myself.

For R2 I arbitrarily chose 10k- an easy number to work with, low enough current so as not to load heavily but high enough to suppress drift, readily available in 1% tolerance.

A lot of manufacturers will have a means of requesting samples on their website. The issue with switches and potentiometers is that they don't change much, so there is nothing new to attract innovation. If you only need one or two and the distributors in your area are charging too much, one of the fellow hobbyists will probably be happy to share if you pay for shipping.

This si a cool little device! A few years ago I had a job that included scrapping power supply modules, and I noticed a few reusable parts on them. The TL431 was one such. I have a film jar full of them (very short leads though). Then I became aware of a PCB promotional offer, so I included a daughterboard in my submission. It works great! Two SMT resistors, one TO-92, and two header pins (it also workd for LM334 and LM335). That's what I used on my PIC programmer for both of my zeners. I also used one to make a 2.55V reference (should have been 2.56) for a projet that monitors it's own supply voltage (still not done- the human interface was a bad design, and right now everything is packed up).

You sure are taking on a lot RF. I hope you don't get bogged down and frustrated. That willl be a nice toy when it is finished. The tuning on the original is by an R-C oscillaotr, but only one so everything is in tune with itself. You asked about microcontrollers earlier. Do you have programming experience? You haven't been here long, and your profile doesn't say much. I don't know what priorities you ultimately have for bells and whistles, but I recommend a method that allows you to get something together that resembles the project long before it is finished. I have too many things laying about that I never finished because I improved them before I had anything to show for it.

I think you meant to put this here, and not in my message box. I have no way of judging your competence from here, and this is a hazardous project. As such I don't know how much help I will give you, and it does depend on the information available to me. How many cables enter the junction box you wish to install the radio controlled switch in? What are the dimensions of the device? Power requirements? What voltage are you working with? How much space is available*? On the last question, if you don't already know then I can't tell you how to find out (for liability reasons).

How many cables come into the j-box? If there are two or more, then you almost certainly have a neutral wire to work with. If there is only one, then the switch is downstream of the light that it controlls, but you may still have a ground wire available. For inline wiring without a neutral/ground, you will have to use very little current in the "off" state so that the light will stay cold. Do not assume that the fixture is safe to mess with in this condition- it is still active, just not glowing. Either way you will need a switching device, and whether mecanical or solid state you will need to be certain that it will not heat up excessively. I believe the heat is one of the contributing factors to dimmers only being available up to 5A. With that in mind, until you find out from someone who is an authority on the subject, you should assume that 5W is the maximum that can be radiated from a standard junction box. That being said, since the controller will need to be powered when the light is on, the load depends heavily on the voltage requirements of the controller. For example: I will assume that the "off" current will be supplied by a capacitor in series with the load to reactively limit the current. The controller is connected to an optimized filter/regulator and a bridge rectifier. Total losses through the recitfier and regulator are 2.5v and the controller needs 3V. That's 5.5V, and it won't change when the load is turned on. Five watts over 5.5V, that's 0.9A. What's more, you'll have to find a way of using 900mA at 3V when the load is on, or your regulation will get more complicated. Far from impossible, just sticky. I hope you can shoehorn it in the box. <edited for spelling>

Someone from Central Semiconductor called me a few days after my sample request. Some quesitons were asked (reasonable ones), some answers were given (true ones). Not all of the items I asked for were in stock. The CLDs were changed to a different value. One of the TRIAC PNs was altered, another omitted, and a third had only nine in stock. Long story short, I got what I asked for if it was available. I also got three data reference manuals. My request to Microsemi has not yet been answered. Nor has Ramtron responded.

Someone in this area uses greasel tool He has two independant tanks- one for vegetable oil and one for diesel. The vege oil tank gets it's heat from engine coolant. He starts on diesel and switches over after a few minutes

Have you considered using LED? Bright by day and dim by night. If you don't mind committing a microcontroller to the display, then it should work nicely. If you have already decided that it must be LCD, then one I can suggest for economic reasons is the screen from an older Nokia cellular telephone if you can rescue it from the garbage can. The LCD is about 20*30mm- about the minimum size you would want. It uses a 5 wire serial protocol. The display will require some reworking to mount it, and 1-2k of program space (including font).

I can see why you are looking for other options. The chip is still available (somewhat), but at $40 I would examine other avenues as well. I will look for a few distributors. If a good price appears, I will let you know.

Are you on a time constraint for this project? Did the person who designed it offer the code? Did same person offer preprogrammed chips? Not too many hobbyists that I know of use Philips microcontrollers. The most popular are Atmel, Microchip, Texas Instruments, and multiple sources of 8051 variants (which I suppose this is). Sorry I can't be more helpful.

Hmm. Perhaps I was being deliberately obtuse. The theme of vonage advertisements appears to be anti-nerd.

Request them all in the same session.

Maxim: digital pots, I/O expanders, real time clocks, nonvolatile memories, temperature sensors, LED drivers, switching regulators, voltage references, rs-2322 interface... Allegro: hall sensors, current sensors

You are asking STATE_MACHINE, but I will tell you my experience. Samples I have requested from Texas Instruments, Maxim, Analog Devices, MIcrochip and Allegro have been shipped to me without complication. Some of the items I requested from TI were rather expensive. I have requested samples from Fairchild and National, and received them with some complication. Now I only ask them for items nobody else has. The requests submitted to Atmel, Ramtron, Microsemi (two years ago, I'm trying again), Sensirion, and two others I don't remember the names of, were all ignored or denied.

Hello Roomi. There were a few mentioned by you and STATE_MACHINE that I had not known. It will take some time considering the season and road damage in my area. I will let you know when I find out.

Under perfect conditions, trying to get morethan 208mA will exceed USB spec. If you can get 160mA you are doing well.

First off, the priest thing is humor. "I'm a ttibetan ppreist" is replacing the default line "I'm a llama". In my country, most people with english as a primary language and nearly everybody with it as their only language pronounce "llama" as "lama". The correct form is "yama", so when they are speaking of an animal they are saying "priest" instead of "camel". So I put an extra letter in front of "Tibet" and "priest" to poke fun at them. As for the subject of the query- the wire I am using is 24AWG, which is about 0.084 ohms per meter. It is the same for the telephone cable (cat3, 3 pair, bare ground with foil shield) as for the ethernet cable (cat5e, 4 pair, no shield). I have found that some applications alloow for and require power transmitted over the unused pairs (+/-48V, 350mA), which does come within the specifications for a class 2 low voltage supply for residential housing. Many of the gadgets I might dream of hanging from a media drop will use a single supply much less than 48V. I also want to avoid the complications involved with ground currents interfering with communication. The work-around that seems obvious is to use a negative supply to provide a current path to keep the ground (reference) unloaded. I suppose this is an obscure niche- trying to provide a ground impedance at least an order of magnetude lower than the supply wires can give.

Wow, there're a few new ones I haven't sampled yet. As always I re-enter my name in the company field (I keep good company). My title describes what I do in my free time. One wanted more than one line of street address, so I specified my brewing shed. I will find out soon enough.