Generally speaking, there are three types of stamping dies which are widely used for the production of manganin shunt resistors: simple dies, combination dies, and progressive dies. We develop different kinds of stamping dies, according to the properties and production quantity of a shunt. Of course the classification can also be applied to the stamping dies of busbars or copper lugs for current transformer or latching relays.
Simple dies are cheap, cost only a few hundred dollars for each set. It need only a couple of days to develop a new. But it’s not precise in dimensions and the effectiveness in production is also very low, as the EBW strip or manganin/copper strip should be feeded manually.
Combination dies, or compound dies can punch the inner and outer profile of the required shunt at on time. So, there’s no need to position the material more than one time, and we can get precision dimensions. But the drawback is that the cost is higher, and the operator should fix the strip or plate one by one. So, we only use them to product complicated shunts of big size, such as C shape shunts.
Progressive dies can punch the shunt automatically, one the strips are feeded. It’s very important for large-scale mass production. But they are very expensive and may cost more than 2000 dollars to develop one set. We usually use them to produce EBW shunt resistors of hugh quantity.
The advantage and disadvantage of each type of stamping dies are summarized as below table.
After stamping, other production processes are required to make a final shunt, which are introduced as below.