Instant-Read Thermometer: Digital, with a Stainless Probe That Pivots on the Case (Cook, US 5,018,875, 1991)

A pocket digital thermometer. A thin stainless steel probe with a thermistor in its tip pivots on a small, flat-sided case, so you can push the probe into food and turn the display to face you. A button cell runs a chip and a liquid crystal display, and a push button updates the reading at once. The angled case will not roll off a table. Result: a thin-probe digital thermometer for food and air. Source: T. A. Cook (PSG Industries), US 5,018,875 (1991). Unknown: the circuit, the range, the case size. Picture: the patent drawing.

중급

Unknown

안내

Make the probe

Cut a type 304 stainless steel tube about 0.166 in (4.0 mm) across and 5 in (120 mm) long, and close one end. Set a thermistor inside the closed tip and run its two wires up the tube. Aluminium or titanium would also serve.

이 단계의 재료:

스테인리스강 관1 probe

NTC 서미스터 키트1 thermistor

구리선1 interconnecting wires

필요한 도구:

쇠톱(핵소)

인두

Mould the pivot boss and case

Mould from ABS a cylindrical pivot boss with a recess for the probe's open end and a channel right through it for the wires. Mould the case in an upper and a lower half that snap together, wider at the display end and tapering to the probe end so it cannot roll, with two projecting supports at the probe end, each with a pivot hole. Not given: the sizes.

이 단계의 재료:

ABS 펠릿1 boss and case

필요한 도구:

사출 성형기

알 수 없는 치수

Fit the electronics and assemble

In the case, fit an integrated circuit that turns the thermistor's resistance into a reading on a liquid crystal display at the wide end, with a push button beside it that updates the reading at once. Add a compartment for a 1.5 V button cell (Eveready E675, IEC R07) under a cover that locks with a quarter turn. Push the probe into the boss, lead the wires through the channel to the circuit, and clamp the boss ends in the pivot holes as the halves snap together; friction holds whatever angle you set. In use, push the probe in, turn the display to face you and press the button. Not given: the circuit (the patent points to US 4,536,851).

이 단계의 재료: