Non-isolated Off-line AC to DC Power Supply – This compact efficient circuit can provide up to 100ma of a regulated 5 volts from an AC power source ranging from 20vac to 120vac.
Off-Line Compact Universal Linear Regulator – Supertex Semiconductors
Off-Line Power Supply Does Not Require Filtering to Meet FCC Emission Requirements – DN175 Design Notes (Linear Technology)
One 9 Volt Battery gives +18 +25 +33V – This circuit is based on MAX1044 is a charge pump converter.
MINIATURE ISOLATED AC/DC POWER SUPPLY
This circuit uses a novel approach to produce a fully isolated and regulated 5 volts @30ma from the 120vac power line. It uses two tiny SCRs that alternately discharge two capacitors through a miniature high frequency transformer. The voltage spikes produced through the transformer are rectified, filtered and regulated. A very common 8 ohm audio impedance matching transformer can be used for the transformer. Published in EDN, Feb. 17, 1992
CAPS PROVIDE VOLTAGE BOOST TO SERIES REGULATOR
This circuit adds some capacitors and diodes to a traditional transformer type series regulator circuit to extend the normal operating range. It can insure regulation during low line voltage conditions or it can squeeze a few more watts out of a plug-in-the-wall power adapter power supply.
LOW POWER 12,000 VOLT POWER SUPPLY
If you need about 12,000 volts DC for an ion generator this circuit might be the ticket. It draws power from the 120vac power line but it uses a small 6KV camera flash trigger coil. The output signal is isolated from the power line. Although the circuit can only deliver about 5uA of current it can produce dangerous shocks, so be careful.
240VAC TO 5VDC POWER SUPPLY
This is simple way to power some 5v logic from a 240vac source. If a 120vac power adapter is used, the circuit will also work for 120vac power lines.
1.5V to 5V Converter – In many cases can be very handy to be able to convert 1.5V to 5V. Then you can power microcontroller or LED from a single AA or AAA battery. It is simple to do this as there are special IC�s as MAXIM MAX1674 or MAX7176. This is step-up DC-DC converter that can convert voltages from 0.7V to any in range from 2V to 5.5V. MAX1676 have already preset pins for 3.3V and 5V, that makes easer integration in 3.3 and 5V circuits. IC can dissipate up to 444mW.