I am an electrician by trade but I also have some electronic background. I don’t know that much about electronics though but I need a simple circuit that can help me switch 230v using a low voltage supply (I would like the supply to be run from the same place – so the low voltage run from a transformer from the 230v supply instead of a battery). Thanks.

I’ve got an Amana 93HQ furnace, a Goodman CKL36-1L AC unit, and a Robertshaw (unk model) digital thermostat. All are about 2-3 years old.

Several days ago, we lost power to my house during an electrical storm. The power was off for several hours. Eventually, the utility company replaced the (ancient) transformer and restored power. I do not know what else they may have done, as I was at work when power was restored. I know a loud lightning strike woke me, but I do not see any evidence of an actual strike at the house.

Upon returning home, I found that my DSL modem, my garage door opener motor, and my digital thermostat were not functioning. All other electronic devices seem fine (TV, Wii, etc).

The modem power supply had been humming for a while, and my electrician friend said that garage door motors seem to be sensitive to the surge after a transformer hookup. Particularly if they hooked the house to the transformer, and -then- hooked the transformer to the grid. He said this seems to create issues more often than hooking the transformer to the line, and then the house to the transformer. I have no idea how things were connected, obviously.

Upon looking into the thermostat issue, I found that the 3A fuse on my furnace board was blown. Replace, blows again. With some trial and error, I found that the circuit is -fine- in the heat, or fan-only settings. It’s only when the thermostat tries to activate the AC that an issue occurs. Discussion with an HVAC acquaintance of mine led me to think it may be the contactor.

I pulled the access cover from my AC unit, and manually pushed the contactor…everything seems to work normally. Fan spins, I can hear the compressor fire up, etc. Try to activate from the thermostat, though, and the 3A fuse blows. I also pulled the low-voltage wires at the furnace board (wires which run out to contactor on AC unit). When this is done, the thermostat can be switched to "Cool" without issue. Obviously the AC unit doesn’t engage, but no fuses blow.

Ideas? Could the surge of power (after transformer replacement) have hosed the coil in the contactor? Is there a way to test this, prior to replacing the contactor? Is there a way to get 24V power to the contactor (to see if it engages) without tripping the fuse on the furnace board?

Other thoughs, suggestions, or advice?

on the same circuit a potentiometer that controls the light "dimness" is fried. What would cause both the circuit board on the ceiling fan receiver to fry(i opened it, it is literally black inside) and the control dimmer to fry. An "electrician" sent his helper over to wire the house and I want to know what he might have done wrong.

Trying to power up an intercom system in my home that has a cd player. The intercom has a transformer for it and the cd player has a transformer for itself. Not being an electrician but a do-it-yourselfer, I attempted to power up the unit by sharing a neutral and a hot from a nearby light switch. I connected this to to intercom transformer (hot to hot/neutral to neutral) and then looped over to the transformer to the CD player. Both units require a 15 amp 120v line which I checked. It is a 15 amp circuit I am using. When I powered up the intercom, the clock display came on but it wasn't really working. It made a dying cow sort of sound like when the batteries are going low on an electronic toy, etc, and I noticed the light from that light swich was on and was very dim even though the switch was turned off. I looked over the intercom manual and it says it needs a dedicated power source so as not to get interference from other items. Is this the problem? Thanks.
Some points:

This intercom/cd combo is brand new
I have wired everything myself per instructions and have double checked everything. All looks good. It just seems like with the power source I tried it wasn't getting enough juice. Even the radio wouldn't come on…only the digital display would funtion properly. Thanks.

I have a 89 Camaro RS that has electrical issues up the wazoo. The previous owner hotwired different circuits to bypass a failing computer. So i paid 0 to get the wiring put back to factory, but now I have another problem.

Driving down the road one day, my car suddenly lost all power and sputtered to a stop. I was on my way back to work and was in a hurry. It ended up starting back up like normal after a few minutes and continued driving. Not much further it died again and didn’t turn back on.

I don’t have hazard lights, any ignition response whatsoever, radio, power windows, or gauges. I do have head lights and lights backlighting the gauges. My rear hatch opens, and other than that it is all out. I checked to make sure the battery terminal was connected.

I am definitely not an electrician and would like to receive some sort of guidance regarding this frustrating situation. Thanks in advance.
Any links to pictures would be helpful

Hi,

Can you please offer any advice on my business idea? Do you forsee any problems please?

I have this idea for a small business. I have done some research, and found that there may be a demand for this product. I want to create a small electronic device, that people can use to experiment with high frequency sound.

I am planning to just sell a small transducer (to create the sound) and a photo copy of a plan for an amplifier (plus circuit diagram) which people could take to any electronics technician, like and electrician and have built.

Once I pay to have the transducer designed, it should be able to be built for under us pc in asia. The complete package that I sell (just transducer and photo coppies) should be no larger than a packet of cigarettes, and weigh less than 200g. I should be able to ship it cheaply through the standard mail to just about anywhere in the world. I am hoping to sell this product for under 0us.
There are some possible legal issues with the final product having the possibility of being abused. It could be used to harass people and possibly cause accidents, so I am going to go to a consumer goods solicitor to have a short contract drawn up to supply with the shipped item. Also, the device may have enough power to deafen someone if aimed at their face so I am going to recommend hearing protection. Additionally the device may have enough power to paralyse someone if used in a certain way. Also, the device could inadvertently electrocute the person using it, so I am going to have it designed to run on a 12volt input, have some insulation added to the outside of the transducer, and try to get the engineer to reduce the current whilst maintaining voltage, in an effort to salvage as bigger percentage of the power as possible, and hopefully reduce the power to a non lethal level. Also, I am going to have a clause written into the contract to cover this.
I am hoping to market my product directly on ebay and possibly open a yahoo store. Also, I would like to wholesale it to a number of parties who may be interested in distributing it.

This is just an idea at the moment and may take a long time to develop. In the interim, I am planning to experiment with the smallest 15kHz transducer I can find, and hopefully I can get some firmer ideas about frequency and power.

Can you guys please offer any ideas or suggestions about my business idea? Do you forsee any problems please?
I think the main issue is not so much the danger of this product itself, as insulation can be used, and reduced power specifications can be determined for the transducer. The main issue seems to be with the danger of high frequency sound between 15kHz and 20kHz and the high level of sensitivity humans seem to have to it. As far as I can see there are no reputable published research articles on this which I can find on the web. I find this fact very surprising when one considers all the implications. Some possiblilities are that high frequency sound could be used as a harassment method (can go through wall of a house), to cause an accident (like a car accident), or in some cases even temporarily paralyse someone. The noise pollution could keep people awake for extended periods of time, it could prevent people from being able to study, and generally prevent a landlord or person renting a property from having "the right to enjoyment of the land" the main founding real estate principle.
I think it would be the responsiblity of someone selling this device to include some information about the dangers of high frequency sound between 15kHz and 20kHz. I will have to speak to a consumer goods solicitor about having a short contract of warning about the dangers.
I think I will also have to speak with the govt. dept. which manages business and product safety in my state. Also, even if it is legal for me to sell in my state, I may have to check with a solicitor how I can sell it overseas on the web.

I have a 89 Camaro RS that has electrical issues up the wazoo. The previous owner hotwired different circuits to bypass a failing computer. So i paid 0 to get the wiring put back to factory, but now I have another problem.

Driving down the road one day, my car suddenly lost all power and sputtered to a stop. I was on my way back to work and was in a hurry. It ended up starting back up like normal after a few minutes and continued driving. Not much further it died again and didn’t turn back on.

I don’t have hazard lights, any ignition response whatsoever, radio, power windows, or gauges. I do have head lights and lights backlighting the gauges. My rear hatch opens, and other than that it is all out. I checked to make sure the battery terminal was connected.

I am definitely not an electrician and would like to receive some sort of guidance regarding this frustrating situation. Thanks in advance.
Any links to pictures would be helpful