Doing away with batteries in "toys"

[Normk]

I often buy this type of voltage regulator in order to power various small loads such as two-way radios, and various other small devices:

http://www.ebay.ca/itm/3-pcs-LF60CV-Fixed-Voltage-Regulator-6-Volts-500mA-LDO-/110479348804?pt=LH_DefaultDomain_0&hash=item19b9151444

They are very easy to use as they only require attaching four wires (two to the centre ground pin). One ground wire goes to the negative of the power source and load, while the other two pins go to the power source positive and to the load's positive. Note that it is best to ensure that these are listed as + 6 volts in order that the common ground terminal is negative as this makes them easier to hook up. The limitation is that the power source must be higher voltage than the load but that's obvious.
They are available in many other voltages so I simply select the desired voltage when purchasing. The price for three of these, for example, was about $5.00 which is far less than for the eight AA rechargeable cells needed to power the two GRS "walkie-talkie" radios we use for communication between our motorcycles. This also avoids dead batteries by running off the bike's power.
I used an eight volt one to replace the much more expensive instrument voltage regulator for our motorhome.
Here's another useful little creature: http://www.ebay.ca/itm/130683297102?...84.m1439.l2649
This one has a tiny adjustment screw which allows voltage to be adjusted. I plan to buy another one for permanent conversion to an adjustable battery charger with attached voltmeter and ammeter. The unit is self limiting in terms of current to just over 1/2 amp but that eventually gets the job done in most cases. I'm in the process of charging three six volt batteries from some Honda CT90 trail bikes being worked on for a friend and no longer own a small capacity 6 volt charger. Of the options available, this was the most simple.
Just thought you may not have considered using these and that the option might be useful.
Norm

[Dogma]

What is the other circuitry found in something like a cheap power point (cigarette lighter) to USB charger? Filters? I disembodied one of these (and potted it. Nothing but through-hole components on the board) to charge my phone on the bike. There was a lot more in there than just one of these regulators. I wondering if there are any applications these would be inappropriate for.

[posplayr]

there are thermal limit if supplying 500 mAmps.

I used a similar device at 12V for a voltage reference for gauges. I used a piece of thin strip copper mounted under my gauges to provide enough surface area to dissipate the heat.

http://www.thegsresources.com/_forum/showthread.php?t=161413&highlight=voltage+regulator

[Normk]

Some users will place a capacitor across the output as a filter. Since I am old and not longer recall how to calculate the capacitor value required, I usually just jumper in various values from my junk box until an unwanted noise goes away if encountered. The walkie-talkies we use for interbike communication seem to not care about any noise from the voltage regulator.

Of course one needs to take into account the polarity and voltage of electrolytic capacitors as they can make quite a "pop" if wired in reverse.

I often use recycled devices such as power adapters as you noted. Check the rating of the adapter (usually in Watts or milliwatts) to ensure that it exceeds the requirements of the toy. If not, the adapter my burn out or toy not function properly. A quite reliable check to confirm is to connect your voltmeter across the output of the power supply when it is connected to the toy. Power up and apply the maximum load such as transmitting from a GRS radio and monitor the voltage which should remain near the device's rated voltage.

Lots of little projects can be undertaken with simple components off EBay or other on-line suppliers. I strip out the diodes, transistors, resistors, etc. from stuff before it goes into the bin or to the recycler. The salvaged stuff often makes useful opportunities. I matched up a salvaged transistor to one with a split case and was able to repair an inverter for a friend. No idea as to what was its role but works now.

Three 6 volt bike batteries now charged for the CT90 Hondas I'm redoing for a friend were all charged with the little 1/2 amp adjustable power supply listed in the second link of the OP. Otherwise would have had to stack some diodes, make up a resistance voltage divider or some other more involved approach.

What is the other circuitry found in something like a cheap power point (cigarette lighter) to USB charger? Filters? I disembodied one of these (and potted it. Nothing but through-hole components on the board) to charge my phone on the bike. There was a lot more in there than just one of these regulators. I wondering if there are any applications these would be inappropriate for.