In modern times, there is a broad range of equipment – in the home and in institutions – to help overcome discomfort of the sick or the infirm. Modern technology expends large efforts to develop support equipment for these unfortunate people.
Most of these devices operate on electricity, which means that on Shabbat there is a problem to turn them on for a sick person who is not in mortal danger, or if there is doubt about mortal danger. Examples are medical devices meant for children, inhalation equipment, devices to overcome breathing disorders, inflatable mattresses for pressure sores, and so on.
In addition, institutional equipment, such as in old age homes or hospitals, is often portable and therefore cannot be plugged into a permanent outlet for all of Shabbat. An example might be an intravenous pump that a patient can move around with him, so that he or she will be able to leave the bed. There are many other examples of such equipment. What can be done on Shabbat? How can the device be removed from the power outlet? (A pump might use rechargeable batteries, but even then the act of disconnecting it from the power source is prohibited on Shabbat.)
Similar problems occur in the realm of security. Many instruments, such as common communication devices, beepers, and so on, use batteries that must be changed or recharged. What can be done to lessen the desecration of Shabbat involved in such routine security operations?
In order to solve the problem of using such equipment on Shabbat, The Zomet Institute has developed an electric outlet that operates on the principle of gramma (indirect action). The outlet acts as a bridge between the normal electric network and the equipment, transforming it into a device which can be used on Shabbat for essential needs.
Before Shabbat, the outlet is connected to a regular electric power source. It includes a gramma mechanism which checks the status every 15 seconds for a duration of about one millisecond. The electrical equipment is plugged into the gramma outlet and the switch is turned to the "on" position. Nothing happens until the next test pulse, when the current will be turned on. The equipment is disconnected in a similar way. The switch is turned to the "off" position, but nothing happens until the next test pulse. The gramma outlet has a safety feature so that the switch will not work if it is flipped exactly during the millisecond-long test pulse.
This universal gramma outlet can be used with any 220 volt electrical device.
For details and prices, contact The Zomet Institute.