This circuit is boost regulator,
input volt DC12V for output DC28V (28v relay)
The circuit is built around the LM2585,
and uses the energy stored in an inductor to boost the 12v to 28.
The circuit does it’s switching around 100 Khz,
but generates no noise if SMT components are used.
…
Note
1. A short-circuit on the output will kill U1 and D1. Always use a 1 ohm 5w resistor,
or a 2.5A fast fuse on the 12v input lead.
2. Do not omit the LED (D2); It provides a visual indicator of a properly operating boost condition,
but more importantly, it also provides a minimum load for the output,
preventing an output “spike” which will otherwise
appear when the load is disconnected abruptly.
3. Keep the ratio of r2 and r3 to 22 or less to keep the output voltage
within the ratings of C4 (C4 on my board is rated at 35wvdc).
This ratio plus 1, multiplied times 1.25v, determines the output voltage.
Source: http://www.w6pql.com/12_to_28v.htm
Related Links
All circuits of Switching Regulator IC
All circuits of Step up dc converters
All circuits of Step up voltage converter
All circuits of LM2585
DC Converter 12V to 24V 2A by IC 40106 and Mosfet BUZ11
dc converter 12V to +30V – 30V for car with IC SG3525
12V to 16V DC/DC Converter with LM2577
12V to 18V step-up DC converter by IC 555
SG3525 DC Converter 12V to +35V,-35V
12V to +-20V converter for audio amplifier
This entry was posted on Sunday, July 8th, 2007 at 11:45 pm and is filed under dc converter, Power supply.



