# Looking for ttl relay board

#### djreiswig

Joined Aug 8, 2008
98
I'm looking for a relay board something like this
https://ebay.us/vSs9C5
I have a ttl signal (5v) from an Ethernet smoothstepper output from a cnc table.
I would like to use a 12vdc relay to switch 120vac.
The seller of this board says both the signal voltage and the relay coil voltage need to be the same. I'm wondering if that is really the case. I don't have enough electronic experience to know how it works.
I really want to control up to 8 relays if such a board exists, or I can use multiple separate boards. Not looking to spend a ton on this.
Can anybody give me a hand?

#### ericgibbs

Joined Jan 29, 2010
8,581
hi,
Looking at the data on eBay, the relays have 5Vdc coils, the control logic levels are TTL.
Why do you want to use a 12V relay when a ready made 5V relay module would switch the 120Vac mains.?
E

#### djreiswig

Joined Aug 8, 2008
98
hi,
Looking at the data on eBay, the relays have 5Vdc coils, the control logic levels are TTL.
Why do you want to use a 12V relay when a ready made 5V relay module would switch the 120Vac mains.?
E
My 5v power supply in my cnc control box isn't large enough to power relays, but there is a 12v supply available that I can use to run the relays. That is why.
Maybe I linked the wrong one, but he has a 12v board listed. I'm wondering if I can drive the inputs on that one with 5v.
Also, is the 5v input + or -? I think the ESS outputs a +5v, but it might be switchable to output a -5v. Not sure.

#### ericgibbs

Joined Jan 29, 2010
8,581
hi dj,
He does not state the control voltage on his spec, just the relays 12v.
I suggest you email him regarding the control input voltage.
E

Description:
Features:
With optocoupler insulating and PLC control.
Controls AC 250V 10A, DC 30V 10A.
Triode driver.
With holder screw holes for easy installation.
Small PCB Board: 53 X 40 X 18 mm/2.09 X 1.57 X 0.71 in
With red indicator light.
Low/High level trigger.

Ports:
Left:
JD-VC: Relay power port
VCC: Module power port
GND: Connect ground cord
Right:
VCC: 12V module power
GND: Connect ground cord
1N1-1N82: Relay control port
Included:
1 X Relay Module Extension Board

#### djreiswig

Joined Aug 8, 2008
98
I contacted him and in broken engEngl here was his response.

12V relay need use 12V input
5V relay need use 5V input
Nit canoot mix mode
5V input for 12V relay

We recommed another model
https://www.ebay.com/itm/262458427505
if you need switch High / Low Interoperability

here you can use switch to set 5V or 12V mode
= you no need 12V and 5V relay

I asked him for a manual for the one he suggested so I can understand what the dip switches are doing, but he said I should just buy one and try it. Not sure how I can try it if I don't know how it works.

#### DNA Robotics

Joined Jun 13, 2014
494
2 other answers while I was working on it but...
This is the 5 volt version. It looks like active high or active low are user selectable on both of them.

• Voltage: DC 5V --- 7.5V
• can control 10A 250VAC, 10A 30VDC Load
• Optocoupler isolation, input and output power selectable independently controlled.

This one uses a 12 volt supply but can use 5 volt control logic.

https://www.ebay.com/itm/USA-DC12V-Four-Channel-Relay-Module-4-Way-Optical-Coupling-Isolation-Sensor/263998457481?_trkparms=aid=555018&algo=PL.SIM&ao=1&asc=20131003132420&meid=206e62a586434770a97a9e1710f55ec0&pid=100005&rk=2&rkt=7&sd=262458426089&itm=263998457481&_trksid=p2047675.c100005.m1851

• Voltage: DC 12V
• Three, can control 10A 250VAC, 10A 30VDC Load
• Optocoupler isolation, input-output dual power optional independent control (DC5V/12V/24V).

#### djreiswig

Joined Aug 8, 2008
98
I was looking at that 12v one, but I couldn't get a straight answer from the seller. So your pretty sure I can control it with 5v and run the relays with 5v? Would the input signals need to be +5v or -5v on that? I know it needs to have both hooked up for power, but I'm wondering which polarity the signal pins are. I saw some boards have a jumper to switch, but this one doesn't appear to.

#### ericgibbs

Joined Jan 29, 2010
8,581
hi,
If it is a TTL 5V control input it will be 0V to +5V.
E

#### DNA Robotics

Joined Jun 13, 2014
494
Be careful with this guy. The 12 volt one that I linked to says 24 volt coils on the relays.
The one that you linked to says 24 volt in the title but 5 volts everywhere else.

"Contact after the arrival of technology manual, e-mail sent."

Maybe you can get him to send the manual

#### djreiswig

Joined Aug 8, 2008
98
I tried and that's all I got. I'll just have to order one and see. He said he would refund if it didn't work. Thanks for your help. I'll post back with an update.

#### djreiswig

Joined Aug 8, 2008
98
Well, it appears that even though the auction is a best offer, he's wanting full price (which I guess I'll pay since I haven't found anything better). I made a couple of offers and told him since he provided limited information and no manual and I wasn't sure it would work for what I needed I didn't want to pay too much.
He finally sent a manual. It says it uses dual voltage and that if they are the same you can use the jumper. So I'm under the assumption that since the voltages can be different, then one must be in the 0-5v range for the control and the other must be 12v for the relays.

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#### ericgibbs

Joined Jan 29, 2010
8,581
hi dr,
If these module Inputs are connected to the onboard Opto-coupler in the same way as my relay modules [ Amazon], you have to pull the Input pin low to energise the relay. The Input pins are at approx +5v when open circuit, you should check that with a DVM.

Also note the 0v/Gnd PCB track is always connected to the 5V and 12V sections of the modules circuit, not fully isolated.
The relay contact PCB track is isolated from the logic track.
E

#### DNA Robotics

Joined Jun 13, 2014
494
Item #: 35360 MP
Sale: $6.95 Look around that site. They have one with 8 relays but it is active low to operate. Thread Starter #### djreiswig Joined Aug 8, 2008 98 DNA Robotics - I don't have a 5v supply capable of driving relays. I need to use 12v for the coils. ericgibbs I'm wondering if they aea separate since there is a jumper for the + and the -. Why provide both if the - is always connected? According to the Warp9 guy, the ESS can provide a ground on the output pins so it should be fine. He got back to me with$13.50. I think I'll try for \$13.

Joined Jul 18, 2013
18,863
You could always use 5v opto relays such as Opto22, they supply opto-isolated modules which are AC or DC output at different voltages as required, the mounting boards take 4,8,16 or 32 modules and populate as needed.
I have a whole box of them surplus if you do need any.

Max.

#### djreiswig

Joined Aug 8, 2008
98
Do they have 12v coil ones that I can operate with a 5v signal?

Joined Jul 18, 2013
18,863
There is no relay, they are all solid state, opto isolated.
5vdc and 12-24v versions.
They are switched/operated by an opto isolator.
Max.