not enough current for relays?

[Boyan Silyavski]

Hi,
how do i deal when a board / Pokeys57CNC does not output enough current on output 5v pins to switch a external relay / 8 channel relay board 5vdc /??

Leds light but not bright enough and no switching happens.

Do i buy their relay board which has other type of communication with the BOB or there is sth i can do to make the general Chinese relay board work

their board is 30eur versus 10 euro for general low high chinese relay board. and i need 2 .

[Clive S]

Boyan You don't say how you are powering the Pokeys board.
This is from the manual:-

[PoKeys57CNC requires external 6-26V power supply to be connected to the board in order for the device to operate correctly (device may not operate according to the specifications if the external power supply is not present). The device uses switching power converter to scale down the input power supply to 5V. The power supply should be capable of providing at least 2.5W.]

[Boyan Silyavski]

24vdc 150W, but it seems its irrelevant for the outputs


seems it was never meant to do that, look bellow at specs from pdf. I wonder why sb will do such nice board, but that could not power an input of a bloody relay

[Boyan Silyavski]

so what you say Clive, i buy their relay board? and forget about the case

[Boyan Silyavski]

ok, i sorted it out.

it seems they have another product PoExtBusOC16 , which - incorporates 16 high current/voltage open collector outputs which suits applications such as lamps, relays.

[Clive S]

24vdc 150W, but it seems its irrelevant for the outputs


seems it was never meant to do that, look bellow at specs from pdf. I wonder why sb will do such nice board, but that could not power an input of a bloody relay

I read that Boyan but it seem to indicate you can take out the 100R and then get 50mA what do you think. ..Clive

[Boyan Silyavski]

i read somewhere that the relays need more than that, ~80-100mA so at the end i bought the extra boards.

i wish sb simplified the stuff and said- " you need that board and that relay board or output board, cause otherwise you will not be able to do this and that " cause for me 50mA is like chinese.

how difficult would be to do that if you sell a product

[Clive S]

i read somewhere that the relays need more than that, ~80-100mA so at the end i bought the extra boards.

i wish sb simplified the stuff and said- " you need that board and that relay board or output board, cause otherwise you will not be able to do this and that " cause for me 50mA is like chinese.

how difficult would be to do that if you sell a product

I think a lot of small relays will switch at about 15mA https://www.sparkfun.com/products/100 or even less

[HankMcSpank]

Without a diagram of your particular situation, all we have to go on is this....

Hi, how do i deal when a board / Pokeys57CNC does not output enough current on output 5v pins to switch a external relay / 8 channel relay board 5vdc /??

If you get a multi-meter & see what the resistance is between the Pokeys57CNC 0V rail & the relay board's 0V rail ....if it's high resistance , then there's no common path (& therefore this is why your relay's aren't switching).... you will need to link the 0Vs on both boards together. Voltage is always 'with reference to another point' ...i.e. the 5V on your Pokeys57CNC is in reference to the Pokeys57CNC 0V, the 5V on your relay board is in reference to your relay board's 0V...the only way you can make the 5V on your Pokeys57CNC mean anything to your relay board is to commonize the 0V rails on both boards....join them together.