A coffee machine that you can operate on a Saturday morning without violating the sanctity of Shabbat. Alarm systems that neutralize sensors at preset times. A pen with ink that vanishes by itself, so the person can write on Shabbat.

All these wonders and much more are the results of clever inventors seeking technological solutions for the shomrei Shabbat (Shabbat observant) to bypass halachic restrictions on what and what may not be done on the Sabbath.

The Manufacturers Association estimates that the potential for patents targeting the religiously observant and ultra-Orthodox communities in their efforts to honor Shabbat is some $10 million a year. A third of Israeli adults aged 20 or older are observant in some form or other, points out Shimon Yifrach, economic adviser to Minister of Industry and Trade Eli Yishai. "That population is building up buying power, mainly in the consumer products market."

There are already several bodies devoted to supplying technological solutions for the religious community. The most noteworthy ones are the Jerusalem-based Institute for Science and Halacha, the Zomet Institute ("stands at the crossroads of Torah and technology"), the Rabbinical Council for telecommunications issues, and the guardian organization for Sanctity and Education. The rabbinical court of the Haredi community also engages in product approvals, but its affiliation is rather less technological.

These bodies variously supervise and approve (or disapprove) new technologies, sometimes even taking part in their development. They grapple with lofty halachic dilemmas in our rapidly advancing technological world. For instance they might lock horns with the knotty issue of state-of-the-art skullcaps that stay on the head thanks to static electricity: after all, use of electricity is forbidden on Shabbat. They contend with issues of how to "kosherize" cellphones, ovens and refrigerators for use by the ultra-Orthodox sector.

Here are some of the hottest and most intriguing of the patents created for the ultra-Orthodox community, which even the most secular of manufacturers and marketers can no longer ignore.

What's a good Jew to do if he loves a fine coffee before the morning prayer service? Leaving water heaters out of it, if he wants espresso or cappuccino, or percolated coffee, he has a problem. Pressing buttons on a coffee machine constitutes direct intervention in operating the machine's heating elements, which is prohibited on Shabbat. Nor may aficionados of steaming hot cooked java (Turkish coffee) indulge, halachically speaking.

To overcome these problems, a company called G.Li.S. came up with an automated coffee machine, approved by the Institute for Science and Halacha, in which the water and coffee systems operate independently of the consumer.

The heart of the system is a Shabbat timer, which turns the machine on at a pre-set time. Immediately the machine starts heating water almost to boiling point. At pre-set times, the machine emits boiling water, which goes straight down the drain - unless you happen to want a cup of coffee at that point. You merely divert the water tap to the cup manually.

The thing is that G.Li.S's machines are more suitable for the institutional market, such as hospitals and hotels. They aren't efficient for the home, because of the enormous amounts they produce: between 360 to 2,000 cups an hour. Also, they don't come cheap. The price of the machine without the Shabbat mechanism is NIS 26,000 to NIS 45,000, and the machines with Shabbat solutions run between NIS 29,000 to NIS 48,000.

Making or receiving phone calls is also a no-no on Shabbat, but technology has come to the rescue yet again. The Institute for Science and Halacha has come up with a button-free telephone. All the electrical circuits are perfectly closed, which means that in practice - the only thing stopping it from dialing all the time is an electrical disruption caused by an infra-red ray. If an emergency arises on Shabbat, you just wedge a stick into a designated hole on the telephone. A circuit is made and dialing is enabled.

As for writing, the prohibition applies only if what's written is there to stay. It's perfectly permissible for Haredim to write on the sand on Saturday, and they can also use a pen developed by the Institute for Science and Halacha, that uses vanishing ink. The writing takes 72 hours to disappear, which is time enough to photocopy the document or otherwise copy it, to preserve the writing after Shabbat has gone out.

Burglar alarms are prohibited in Shabbat-observant households, even if they aren't turned on come the weekend. The reason is that even when burglar alarm systems are technically off, their systems are working. However unwittingly, every time the tenant moves about his domicile, the system sensors note the movement. Every time a window is opened or closed, an electrical message is sent to the system.

PIMA Electronic Systems to the rescue! The company developed a unique alarm system that passed vetting by the Institute for Science and Halacha. It simply neutralizes the sensors on Shabbat, when the tenants are home. A Shabbat timer clicks the sensors back on at pre-set times.

Adding the Shabbat-compliant mechanism costs no extra. Also, the company found a way to contend with another problem unique to the observant community. Alongside the regular hotline, it uses the services of a shomer Shabbat hotline that does not employ Jews on the Sabbath or holidays, and does not call clientele unless a life-or-death situation is involved.

Every normal household needs a refrigerator and a stove, too. "When we married, naturally we bought a split compartment oven," says Shlomi, a married Haredi who lives in central Israel. "In fact, it's pretty rare to find a religious household that doesn't have an oven like that."

That's because "kosher ovens" need to have two compartments, one for meat and the other for dairy dishes. They must not have a molded connection: isolation of their doors must be achieved through rubber insulation, to prevent vapor from the lower oven rising to the upper one.

In ordinary cases, when the oven door is opened, cold air from the room rushes in. and the thermostat then operates the heating element. The dual-compartment stoves have a Shabbat mechanism that neutralizes the thermostat, to make sure that human agency is not involved in operating the electrical heating device. The oven maintains a steady temperature by operating the heating mechanism at pre-set time intervals.

But be aware: a dual-compartment oven is expensive. For instance Electra's Sauter 60-centimeter dual-compartment model costs between NIS 5,030 to NIS 5,370, while the parallel machine with only one large compartment costs NIS 3,290 to NIS 4,990. Importers of ovens that have won approval from the Institute for Science and Halacha include Electra, Newpan, Mini Line and Birman.

The "kosher refrigerator" is also highly desirable among ultra-Orthodox households, but it isn't as common as the dual-compartment oven. The relatively less stringent Shabbat observers will settle for unscrewing the light bulb that turns on when one opens the fridge door. But the ultra-Orthodox need the kosher model, which like the "Shabbat oven" comes with a mechanism that neutralizes the thermostat.

"You have to use a fridge, even on Shabbat," notes Nathan, a married Haredi living in Jerusalem. "I know of people who to this day won't open their fridge on Shabbat because they aren't aware of the technological advances, or they know of it, but don't understand it and don't want to take chances (of inadvertently violating the Sabbath)."

The added cost of the Shabbat mechanism is not large. For instance, adding the "safety" measure to an Amcor Crystal fridge runs at about NIS 290. Other importers with "kosher fridges" include Sharp, Normande-Clinton International Trading 2000, Mini Line, Golan Westline, and VMG.

As reported in TheMarker this week, the rabbinical communications committee has approved limited Internet surfing by Haredim. But the panel had been set up a year and a half ago because of the advent of third-generation cellular technology among the general population. The result was the "kosher phone."

These phones can't send or receive text messages (SMS) and they can't be used to surf the Internet, either. They can't support content services that haven't received the blessing of the rabbis.

But they can be used for talking, and for certain designated content services appropriate to the community, for instance special riddle contests for the holidays, or information on when Shabbat enters and ends.

Use of these cellphones in the ultra-Orthodox community has become the norm: these days 60% of cellularly enabled Haredim use them. Moreover, the cellular companies are wooing the ultra-Orthodox community with special package deals tailored to the religious. The companies can easily make sure that secular Israelis don't take advantage of the "Haredi packages" - by charging an arm and a leg for calls made on Shabbat.

Pelephone, Cellcom and Orange offer a fixed price of 49 agorot per minute to any destination, while MIRS offers 39 agorot, ditto. Special "kosher" destinations cost only 9 agorot per minute (10 at MIRS). For people who talk more than 100 minutes a month, Pelephone and Cellcom charge monthly fees of NIS 14.90, Orange charges NIS 16.90 and MIRS wants NIS 9.90. But dial a buddy on Shabbat and you'll be charged NIS 10 for the call, in the case of Pelephone and Cellcom. Orange went one better and charges NIS 63.52 a month for violating the sanctity of the Sabbath.