Hi all,
I recently purchased a SPDT latching relay (Takamisawa LZL-6H) and I'm having trouble delatching the relay. The relay has a nominal coil voltage requirement of 6Vdc and requires two opposite polarity voltage pulses to latch and delatch the relay. I know in order to create this reverse polarity signal, an H-bridge can be used (which is what I will be using in the final circuit). I first wanted to see how the relay works, before including it in a circuit with other components, in order to prevent having to debug an entire circuit if something goes wrong.
The problem is, I cant seem to get the relay to unlatch. What I am doing currently is simply connecting the coil pins of the relay to a DC power supply set at 6 V with no current limit. When I use one polarity pulse (manually connecting the positive and negative wires to the coil), the relay latches and the NO pin is connected to the COM pin. Then, when I use an opposite polarity pulse (again, manually switching the positive and negative wires), I can hear the relay make a 'clicking' sound (which I normally take as a sign that the relay jumper has switched between the NO and NC contacts), but the NO pin stays connected rather than having the NC pin reconnected to the COM pin.
I have tried this same procedure with and without a 54 ohm (5 x 270 ohm 1/4W resistors in parallel) load connected to an external 9V battery in series with the COM-NC as well as COM-NO connection to simulate the minimum switching load, but both situations result in the same problem as in the previous paragraph. I did notice that when connecting the coil to the 6V supply, the coil draws around 330mA, which doesn't quite match up with the 80 ohm nominal coil resistance. I bought two of these (in case I broke one), and both act the exactly the same way. So my thinking is that the problem is the method I am using, rather than the relay itself. The link to the website where I bought the relay: http://www.mantech.co.za/ProductInfo.aspx?Item=13M1705
I have searched online using various phrases and keywords, but most of the results either show how to make a latching relay using a normal relay, or just state that an H-bridge type setup is needed to produce the reverse polarity signals. So my question is, does anyone know what I may be doing wrong. Is there something obvious I might be missing in regards to delatching the relay or is this a common problem with latching relays? I have not included any circuit diagram, but if I need to upload one, that wouldn't be a problem since it is an extremely simple setup.
Any help/advice will be greatly appreciated!
I recently purchased a SPDT latching relay (Takamisawa LZL-6H) and I'm having trouble delatching the relay. The relay has a nominal coil voltage requirement of 6Vdc and requires two opposite polarity voltage pulses to latch and delatch the relay. I know in order to create this reverse polarity signal, an H-bridge can be used (which is what I will be using in the final circuit). I first wanted to see how the relay works, before including it in a circuit with other components, in order to prevent having to debug an entire circuit if something goes wrong.
The problem is, I cant seem to get the relay to unlatch. What I am doing currently is simply connecting the coil pins of the relay to a DC power supply set at 6 V with no current limit. When I use one polarity pulse (manually connecting the positive and negative wires to the coil), the relay latches and the NO pin is connected to the COM pin. Then, when I use an opposite polarity pulse (again, manually switching the positive and negative wires), I can hear the relay make a 'clicking' sound (which I normally take as a sign that the relay jumper has switched between the NO and NC contacts), but the NO pin stays connected rather than having the NC pin reconnected to the COM pin.
I have tried this same procedure with and without a 54 ohm (5 x 270 ohm 1/4W resistors in parallel) load connected to an external 9V battery in series with the COM-NC as well as COM-NO connection to simulate the minimum switching load, but both situations result in the same problem as in the previous paragraph. I did notice that when connecting the coil to the 6V supply, the coil draws around 330mA, which doesn't quite match up with the 80 ohm nominal coil resistance. I bought two of these (in case I broke one), and both act the exactly the same way. So my thinking is that the problem is the method I am using, rather than the relay itself. The link to the website where I bought the relay: http://www.mantech.co.za/ProductInfo.aspx?Item=13M1705
I have searched online using various phrases and keywords, but most of the results either show how to make a latching relay using a normal relay, or just state that an H-bridge type setup is needed to produce the reverse polarity signals. So my question is, does anyone know what I may be doing wrong. Is there something obvious I might be missing in regards to delatching the relay or is this a common problem with latching relays? I have not included any circuit diagram, but if I need to upload one, that wouldn't be a problem since it is an extremely simple setup.
Any help/advice will be greatly appreciated!