DNO Under Voltage Protection

Although the DNO does not have an under voltage protection cut-off fitted as standard it is easy to retro-fit this feature. There are two ways to do this;

Method 1; the easiest, is to cut the fuse link F1 [page 4 of the manual] and fit a 500mW zener diode fitted between the 2 adjacent holes. The zener voltage Vz is given by Vz = Vco -4 where Vco is the desired cut-off voltage. For example to achieve a 40V cut off fit a 36V zener diode. The bar of the diode should be to the right hand side as seen on page 4.

Note: Method 1 is not suitable if the DNO brake driver socket is to be used, if this is needed then method 2 should be used.

Method 2; the same value zener diode should be used as in method 1 but it should be fitted to the terminals shown below. The track indicated by the arrow should be cut.