Series 60 Reed
Relays, Near Perfect Contact
Switching: Imagine being able to perform a
contact switching operation using low level switching virtually
perfectly and for many hundreds of millions of switch contact
operations. A rather old electrical principle involves what happens
when two metals unlike each other are connected at one end together
and that end is heated and cooled. A voltage is generated and
can be measured at the other end. This is called a thermocouple
effect.
You have one in your
home. This is a thermocouple device that actually
develops a dc voltage when subjected to heat changes. The
thermocouple junction can consist of two unlike metals, one perhaps
copper and the other Iron, joined at one end.This voltage is very
low, maybe a tenth of a volt at elevated temperature, but
remains a fact. Your home hot water heater uses this phenomenon by
placing several thermocoouples in series to generate a higher
voltage, enough to turn on and turn off the natural gas via a
gas valve arrangement, keeping your water at your desired
temperature.
In a relay, the
switch contacts are of like materials but are ever so slightly
chemically different from each other. During construction of these
relays we choose switches that exhibit switch contact resistance
stability. By using very propietary construction techniques we are
able to maintain equal temperatures at the switch contacts, a
thermocouple junction capable of generating an "offset" voltage
that changes with temperature. Our procedures are unlike
any other manufacturers processings. In the end, we assemble a
finished relay that does not contribute any more than
a microvolt of electrical offset with large ambient or
internal temperature changes. The trick being to keep both ends of
the switch contacts at the exact same temperature so that any
thermocouple effect between the switch contacts is negated. The
result is an extraordinarily electrically stable reed relay capable
of outstanding switching performance over an unbelievable length of
time, almost to good to be true, but a fact. Input switching
voltage and current must be no higher than TTL resistive loads.
Important -----> Tests by an
independent laboratory show that relay life
is equal to or indeed longer that the equivalent solid state
device. Even better is the fact that these
relays can withstand several hundreds of volts standoff between
contacts. Under special design, even standoff voltages of a
thousand volts can be obtained, yet meeting all of the normal
Series 60 characteristics.