Hello Michael. Great comment! There are wo batteries but only one is required. The picture used was from the previous lesson on relays where I showed that two different power sources can be used with relay control. That example was talking about the fact a different voltage can be used to control the relay then the voltage to the contacts of the relay that are driving the load. The benefit to this is that a low voltage can be used to control a high voltage or vice versa. This holding circuit lesson is the second lesson in relay control and I used the same circuit from the previous lesson and justice added the red wire. For holding circuits you can also use two different power sources, but it is not necessary. The picture in the PowerPoint can be replaced with another picture showing only one battery connected to both terminals of each battery shown and it would work. Typically for ladder logic 24 volts is used for the coils and the loads, but this is not always the case because relays are used in many other applications than in ladder logic. Just to sum things up: two different voltage sources can be used, each of them can have different or the same voltages or one voltage source can be used. if only one battery was used both of the two positive battery terminals would be connected and both of the two negative battery terminals would be connected and the circuit would work. moving forward in the lecture, that's exactly what's happening with the latter logic. Although this courses focused on ladder logic, relays are not always used in those type of circuits and are used in many other applications such as cars uncles boats and planes and St lights and many many many other applications where different voltages are used (often low voltage for the coil and higher voltages for the load) I hope that explains some things.
can you provide us with a PDF for that or something like that please
Thank you so so much, great video
In the beginning of video you never explained why their is 2 batteries ? You should have explained this circuit as it is interesting.
Hello Michael. Great comment!
There are wo batteries but only one is required. The picture used was from the previous lesson on relays where I showed that two different power sources can be used with relay control. That example was talking about the fact a different voltage can be used to control the relay then the voltage to the contacts of the relay that are driving the load. The benefit to this is that a low voltage can be used to control a high voltage or vice versa.
This holding circuit lesson is the second lesson in relay control and I used the same circuit from the previous lesson and justice added the red wire.
For holding circuits you can also use two different power sources, but it is not necessary. The picture in the PowerPoint can be replaced with another picture showing only one battery connected to both terminals of each battery shown and it would work. Typically for ladder logic 24 volts is used for the coils and the loads, but this is not always the case because relays are used in many other applications than in ladder logic.
Just to sum things up: two different voltage sources can be used, each of them can have different or the same voltages or one voltage source can be used. if only one battery was used both of the two positive battery terminals would be connected and both of the two negative battery terminals would be connected and the circuit would work. moving forward in the lecture, that's exactly what's happening with the latter logic. Although this courses focused on ladder logic, relays are not always used in those type of circuits and are used in many other applications such as cars uncles boats and planes and St lights and many many many other applications where different voltages are used (often low voltage for the coil and higher voltages for the load)
I hope that explains some things.
are latching relays and holding circuits the same thing?
Yup.