How to convert 110 V DC to 5 V DC?

[hr_rezaee]

i want to convert DC 110 v and DC 24v to DC 5v in simplest way.
do you can help me.

 

[IanP]

Re: 110 v to 5v

That depends on currents you need of 24V and 5V.
For example, if you need some mA only, you can use a shunt resistor and a zener diode ..
If you are after efficiency and Amps then you may consider switch mode DC-DC converters ..
Regards,
IanP

 

[hr_rezaee]

Re: 110 v to 5v

i want to convert 110v and 24v to 5v.
then i give this to input of 74245.
but my problem is
if input is float i have 0v in 74245
if input is 110v or 24v i have 5v in 74245
current does not mind

can you offer some circuit?

 

[IanP]

Re: 110 v to 5v

Use two 10kΩ resistors as voltage divider and connect a 5V zener diode in parallel with the second resistor and 0V.
If you have 110Vdc the current through the first resistor will be ≈10mA (resistor should be rated for 2W), if you connect 24Vdc the current will be ≈2mA. In both cases zener diode will limit the voltage to 5V ..
If nothing is connected the second 10kΩ resistor (rated for 0.25W) will pull down the voltage to 0V ..
Regards,
IanP