Eastwood Instruments' QR10 Family Is a "Revolutionary" Modern Take on the Decade Resistance Box
Offering a range of up to 1Ω to 1.2MΩ in 0.125Ω steps, these pocket-sized decade boxes are built around relays.
Shenzhen-based Eastwood Instruments has launched what it claims is the modern "revolutionary" alternative to the classic decade resistance box: the QR10 family of programmable resistance box.
"A resistor is to electronics is what a brick to building. The resistance substitution (decade) box, which can output desired resistance values, has been invented for more than a century," explains Eastwood Instruments' Frank Li. "However, little has changed for the past few decades — it is still expensive, cumbersome, requires maintenance and [you] have to manual[ly] dial-in settings via mechanical switches."
At its heart, Eastwood Instruments' QR10 is a binary box, an alternative to a decade box, in a swish circular housing. Where a traditional decade box would be configured via switches or jumpers, though, the QR10 is smarter — boasting a compact OLED display, keypad, and a USB Type-C port as standard.
Inside, the mechanical switches have been replaced with relays for, the company claims, improved reliability. The keypad and OLED display provide the ability to program the resistance required and view step point, resistance process value, and maximum voltage at-a-glance — but the box's real potential is shown when it's hooked up to a PC via its USB Type-C port.
"The USB-COM serial port supports any free/open source serial software," Li explains. "The ASCII type AT style commands make it friendly for human beings. Engineers are more aware of the importance of communication interfaces to an instrument, which makes it suitable for advanced applications such as data acquisition and auto-tests — for example, sensor simulation and sensor auto calibration."
Pricing for the devices depends on model chosen, with all enjoying a claimed 30 per cent discount over eventual retail pricing as part of the project's crowdfunding campaign. The QR100T with 1Ω to 1.7kΩ range is priced at $89; the larger QR101T extends the range to an upper limit of 1.2MΩ. Both models offer ±0.05 per cent tolerance, extendable using manual calibration, and 0.125Ω stepping, the company says.
The project's Kickstarter campaign is now live, with physical rewards expected to begin delivery in December this year.