Saturday, November 30, 2013

3V to 9V DC Converters

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Here are some 3V to 9V DC converter circuits that were requested by some of our visitors. It may be helpful to have one of this converters when no 9V battery is available or if you consider that they are too expensive. The first circuit is very simple, it uses the TL496 power supply controller, a coil and a electrolytic capacitor.

TL496 3 to 9 volt converter circuit
tl496 3 to 9V dc converter
The maximum output voltage is actually 8.6V and current is around 80mA.
The input current (the current drawn from the batteries) is 405mA at the maximum output current. Without load the current consumption is 125µA and the batteries life is around 166 days.

Here is another 1.5… 4.5V to 9V converter

3 volt to 9 volt with LMC555
This dc converter is built with the CMOS version of 555 timer. You can get 12V too if you change the zener diode to a 12V version.
3volt 9volt 555 timer
Probably there are more 3 to 9 volt dc converters but for the moment those are the only ones presented in this article.

******Related Topic ******



1.5V Battery to 5V Voltage Converter


 1.5V Battery to 5V Voltage Converter

Wanna recharge your portable music player through its USB power interface, during a winter trip? Or like to energise a microcontroller based circuit using a single penlight cell? Here is an interesting circuit to generate stable and secure 5V DC (at 200mA max) from an ordinary 1.5V AA sized cell. At the heart of this circuit is IC1 MAX756 from Maxim, which is a CMOS step-up DC-DC switching regulator for small, low input voltage or battery-powered systems.

MAX756 accepts a positive input voltage down to 0.7V and converts it to a higher pin selectable output voltage of 5V (or 3.3V). Typical full-load efficiency for the this IC is greater than 87%. Max756 combine a switch-mode regulator with an N-channel MOSFET, precision voltage reference, and power-fail detector in a single monolithic device. The MOSFET is a “sense-FET” type for best efficiency, and has a very low gate threshold voltage to ensure start-up under low-battery voltage conditions (1.1V typ).
assembled circuit
inductor coilThe circuit can be easily wired on a very small rectangular common PCB.All connections should be kept as short as possible. If available,try to add a good quality 8 pin DIP socket for IC1. Note that the power inductor’s (L1) DC resistance significantly affects efficiency. For highest efficiency, limit L1’s DC resistance to 0.03 Ohm or less. A thru-hole type standard power inductor can be used. Similarly, the ESR of all capacitors (bypass and filter) affects circuit efficiency. Best performance is obtained by using specialized low-ESR capacitors.

5 Volt From 1.5 Volt Circuit Schematic

portable 1.5 V to 5 V converter schematic