Electrical plug adapters burn out

[singlesue]

What is it in my house wiring that every electrical adapter that I plug into the wall burns out? Meaning all of my cordless drills, digital clocks anything with the small black square box for a plug doesn't matter what voltage it is burns out. I have had some plugged into surge protectors that I have noticed haven't gone out. What is wrong with my regular electrical plugs that makes these adapters burn out? What can I do to fix it?

[HayZee518]

those adapters are meant to be used with a two wire or two prong receptacle. they are a temporary fix so you can plug in a three prong plug into a two prong receptacle. the green tab goes under the screw that holds the plate to the receptacle. if you have a three wire plug and a three wire receptacle don't use the adapter.

[singlesue]

I may not have explained myself good enough. These are the small black box looking plugs that come in various voltages. My cordless screwdriver plug was 21v, clock was 6v and another item was 12v plugs.

[HayZee518]

ok, now I gotcha! Those plug in power supplies may or may not be DC. You'll have to look closely at the imprint or label. The input in most cases says 110 or 120 volt. If the line voltage in your house goes to say 135 volt, then you'll have problems. a DC power supply can go the course of three designations. first is a regulated bridge rectifier. this uses four diodes back to back to change the AC to DC and uses a solid state transistor or IC to regulate the output. The output may be locked using a zener diode. Extraneous voltage is given up in the form of heat. The second is a half wave diode pair. Two diodes are used to conduct on both the positive and negative portions of the sime wave. The transformer uses a center tap to supply the negative return path to the circuit. Regulation in this crude power supply uses resistors and capacitors to smooth out the DC output. Resistors tend to heat up. Another type of filter system uses a iron core wound inductor and resistors and capacitors for filters. The configuration is called a pi filter. Why yours are burning up? Well, whatever the primary winding [120 volt] is seeing will be transferred proportionally to the secondary winding. The regulation may not like this increase so it gets hot and burns, melts whatever it is sitting in - epoxy, plastic etc. What can be done? I don't think there's anything you can do other than monitor your house's voltage and run your adapters when the voltage is nominal 110-125 volt and disconnect them when the voltage is high.

[singlesue]

Ok I believe your hitting it right on. I was wondering if the ones plugged into a strip surge protector has not burned up if I put in a whole house surge protector would this help protect those types of plugs? Reason being these types of things are used every day like for some of my clocks and battery chargers.

[HayZee518]

plug strips don't have any protection. surge strips that are used with a computer has a spark gap that conducts a high voltage spike to ground. that is to protect the phone line if a dial up modem is used.

[reprosser]

Good info HayZee518,

Any way to monitor your house voltage?

Have you noticed how hot the "black plugs" are running? They can be warm, but should not be too hot to handle. I wonder if the ones plugged into strips are running cooler - either because of the area they are in (maybe near AC vent), or because of the spacing between plugs?

[HayZee518]

if multiple adapters are used on plug strips there's not much free air to circulate around them. one per standard outlet there is. look at the instruction manual supplied with devices. a lot of people just toss the instruction aside then come back when there's problems.