
Andy Roid

Hello All,
I have an 8 relay 5volt relay board, (compatable with Arduino) which I want to drive from my EZBv4. I have made a script to run the ports D8 and D9 on and off for testing. The problem I have is the relay turns on but fails to turn off. I am using an ezb regulator to power the relay board. I thought I power draw might be too high so I changed to a two relay board of the same spec. I have the same problem with this board.
I see some other people have similar issues driving relays from their ezb's.
Any suggestions? I never felt a full answer to the problem was made. I hoped additional hardware wasn't needed. I am beginning to consider building a transistor switching circuit to go between the ezb and the relay, but felt I shouldn't need it. I also considered using an Arduino?
I always thought a relay should be able to be driven direct from the ezb as described in the digital port spec..
Can anyone help.
Ron R
Without info on the board/boards you are using it's guesswork. Provide the datasheets for the boards and someone may be able to give you the full answer. I would guess that it's due to lack of info that's lead you to not having a full answer.
Here's a link to a similar thread on relay issues... Relay issues...
I have two boards which meets my needs. I prefer not to go out and buy more boards and wait for them. I assume if I build a transistor switch circuit the problem will go away.
@ Richard R
Richard, would it be worth hooking up to an arduino? I have an old Uno lying around.
Ron R
I forgot to mention this is a static robot (My project Madame Ninndo) so power sources (3.3 or 5 vdc) won't be a problem.
If you need to use a relay, it should always have a transistor to toggle the position. If you see it say arduino ready or arm ready, 15-20mha is still a lot for a micro to source. You could reverse the connectivity and sink the relay from the ezb, but I wouldn't recommend that either - specifically since you're asking to connect 8 to the ezb!
Follow rich's tp tutorial and create a driving circuit for the relay - or maybe you don't need a relay at all and can do the job with the tp transistor from rich's tutorial.
I also can't see how any of the above has yet solved your question but that's just something else I touched on a while back...
Thanks for your responses. I am looking for the data sheet for the relays. The information you, Dj and Richard R gave me, made me think I must know more about the relays. I believe they are not switched using transistors.
The relay blocks Richard R suggested will fix my issue, and I will be getting them on order, but I would like to continue experimenting to try to get the relays I have working. My project at this time only requires three relays. I will need more in the future.
As Dj mentioned, I want to make a transistor switch anyway so I may try and see if it can trip the relay. I will post how I make out. My project deadline is coming quickly so I need to continue forward.
I thank you for your tutorials and I need to be sure to not forget to refer to them more.
Thanks again to All,
Ron R
Here is the for the two relay board I used for the test. ,
Specification:
This is a 2 Channel 5V Relay interface board, Be able to control various appliances, and other equipments with large current. It can be controlled directly by Microcontroller(Arduino , 8051, AVR, PIC, DSP, ARM, ARM, MSP430, TTL logic) .
5V 2-Channel Relay interface board, and each one needs 15-20mA Driver Current
Equiped with high-current relay, AC250V 10A ; DC30V 10A
Standard interface that can be controlled directly by microcontroller (Arduino , 8051, AVR, PIC, DSP, ARM, ARM, MSP430, TTL logic)
Indication LED’s for Relay output status.
Description:
1. Module with pine le relay control, ac voltage maximum 250 V, ac current maximum 10 A, dc voltage maximum 30 V, dc current maximum 10 A;
2. The 8550 transistor drive, drive ability;
3.Tworking voltage 5 V
4. Has the fixed bolt hole and easy installation
5. Power indicator (green), Two ways of relay status indicator light (red)
Module interface specifications (6 wire)
1. VCC external 5 V
2. GND external GND
3. 1N1-1N2 interchange relay control interface by single chip IO
Using a large current relay, AC250V 10A DC30V 10A
Contact some independent wiring, safe and reliable
Standard interface that can be extended in a variety of development board
With fixed screw holes for easy installation
Suitable for a variety of platforms 51/AVR/AVR/ARM
Size( L x W x H ): 54mm x 47mm x 18mm
Weight: 31g
I plan on using Rich's transistor switching circuit to try to make this work. I saw Steve G and Richard R discuss this issue in a previous thread. I believe the easiest way to be sure this will work is the slave board. I don't mind redundant circuits if the problem is prevented. I am getting parts today and will test it in the next few days.
Ron R
Maybe down the road, offering a relay block which connects directly to an ezb may be a nice add-on?
Ron R
I would buy, rather than build, a plug and play item.
Ron R
Thanks for the driver board construction info and schematic. I made a few changes to run a two relay board. It works Great.
Ron R