USB to RS232 connectivity issue,suggestion and help needed

i have a smart-card reader which is working well with rs232 cable with desktop pc but i want to use it with my laptop connecting with usb to rs232 cable also i want to power it through this cable because reader is also 5v

the cable i want to use
and this the reader schematics
i have simple phoenix card reader…
seniors please guide me about this

Your choice of cable may not work due to the fact that card reader uses MAX232 which is a 5V device (it’s input /output signals are TTL 5V) while the PL2303 in the USB-Serial cable is a 3.3V device. This may cause malfunction. To overcome this issue, you may use MAX3232 which is 3.3V device.

Another big reason for this cable to not work is that it only provides you with TX and RX while your circuit also needs RTS signal which goes to the RESET of the memory card. The only solution to this problem is to look for some other cable which also translates hand shaking signals.

You should try to find a USB-Serial cable which has TTL 5V signals and which translates at least RTS along with TX and RX.

@Ijaz_Ahmed thanks for reply…
and the reason behind using this cable is i already had same (pl2303) cable which had rs232 female end at other side.
thats why i want to use it… also a brand new cable usb to rs232 which we buy from market is also pl2303 but with that i need to use external 12v power source…
so can you recommend any other usb to rs232 converter…
what about this check links plz

one thing more i also directly use this reader with rs232 cable which has only 3 wires …number 5 , 2 and 3
i dont have that with me now otherwise i want to post that cable and pins out here

If you have already successfully used this reader on a real RS-232 port with only 3 wires as you mentioned, then FT232 converter (as in your link) should work.

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Thanks Ijaz for help and does that FT232 will behave the same way like i had used pl2303 cable…
and the cable i mentioned in 1st post i just bought that and its also have 5v output …do i need to give it a try or only ft232 will work…

FT232 based converter should work same way like a PL2303 based converter. I am sure that all TTL level USB-Serial converters have +5V output available. You can power up your smart card reader from this +5V supply.

You can try your available PL2303 converter first. Otherwise Rs.360 is not a big money to gamble on FT232 device.

Good Luck…

yup i will grab that to but let me try with pl2303 cable 1st
thanks a lot Ijaz