Current Sensing Resistors – Check Riedon’s SL series
Sudden current or voltage changes are often hazardous to electronic products. For example, transients or surges that reach microprocessor or memory components can destroy those expensive parts, and wipe out critical programming and data. Many electronic products now include surge protection circuits.
In these circuits, low value resistors sense when the
current is too high so that measures can be taken upstream before the excess current causes damage. Wirewound resistors are a popular choice for these applications. They are inexpensive, available in low resistance values, have low temperature coefficients and good surge‑handling capability. Riedon has served this application for years with their “LO OHM” power resistors.
Now, Riedon’s SL resistors add an additional application advantage. We designed them for PC board surface mounting to satisfy the growing demand for new high density boards fabricated with automated pick‑and‑place equipment.
SL resistors use an alloy strip resistance element, the best design for resistance values as low as 0.005 ohms. The strip element has extremely small inductance. This feature is important where circuits involve very fast rise times; transients, or "spikes," are common in current‑sensing applications.
SL resistors are also more robust. They have only three components: the resistance strip and two leads. We weld the leads to the strip, and mold the assembly in high‑ temperature epoxy.
With wirewound resistors, you get the best stability and lowest temperature coefficient. With strip elements, you also get very low inductance and good response to fast rise‑time transients. Strip and wirewound designs are known for their good surge‑handling capability, an obvious requirement in these applications. You get all these features at a low cost with Riedon’s SL Series resistors.
SMD RESISTORS – RIEDON OFFERS WIDE VARIETY
Check out our SMD resistors available in wirewound, Metal Foil, and Metal Film technologies .
Click here to see the product listing.
Power rating from 0.1 W to 50 W and Tolerances from 0.005% to 10%.
High Temperature ranges also available.
Do you have a special RTD application not covered by “standard” probes?
Riedon has provided advanced power and precision resistor products to OEM industries since 1960. These products "push" the limits for performance, precision, stability and reliability.
We offer no "standard" RTD probes. Instead, we apply our skills to provide custom RTD solutions for our customers.
Contact us. We have an enviable industry reputation as a quality supplier that meets commitments and provides exceptional service…
Balco & Plantinum – Resistors With High Temperature Coefficient
If you're looking resistors with special wire alloys including Platinum and Balco, they are available with temperature coefficient of resistance (TCR) ratings from ‑20 ppm/°C to +6000 ppm/°C. Resistances are from 0.1 ohms to several thousand ohms (depending upon the TCR), with tolerances from ±1% to ±0.05%.
check our data sheet for our precision wirewound resistors. click here
call us at 626-284-9901 or email us at Sales@riedon.com
Fast Rise Resistors
In today's world, pulses are common in electronic circuits. When these pulses encounter a resistor with high reactive components, they are distorted. If the resistor has high inductance, current through it will have a sluggish, slow rise time. The current will overshoot if the resistor has high capacitance. Either condition distorts the pulse's waveform, potentially disabling the circuit's function.
A fast rise resistors reduces t
he distortion and Riedon offers resistor with fast rise option.
Wirewound resistor manufactures sometimes refer to Aryton-Perry windings when they talk about fast rise-time or high frequency response resistors. What are Aryton-perry windings? To make an Aryton-Peryy winding, you first wind a wire layer in one direction. After a layer of insulation, you wind the next wire layer in the opposite direction, with the turns crossing every 180 degrees. This reduces the undesirable reactance components of the winding: its inductance and capacitance.
The re
sult? typical reactive values for these special designs are less than 1μh for a 500 ohm resistor, and less than 0.8pf capacitance for a 1 Megohm resistor. This provides a resistor with a fast rise-time of 20 nsec or less, while retaining the desirable tolerance, TCR and stability that are characteristic of wirewound resistors. So call us to get a quote on fast rise resistors.
Riedon’s Custom Designed Resistance Temperature Detectors (RTDs)
RTDs or Resist
ance Temperature Detectors are widely used to measure temperatures in all kinds of industrial products. In many cases PT100 or PT1000 is specified. PT100 stands for 100 Ohm Platinum RTD, PT1000 stands for 1000 Ohm Platinum RTD.
Platinum, a precious metal, has seen dramatic price increases over the last 10 years. In 1999 platinum was about $400 per ounce, today it is $1700 per ounce and it peaked at $2200 per ounce in 2007. This has caused platinum RTDs to increase in price dramatically.
In the above example, our customer came to us to redesign their current part to make it more cost effective. We were able to shrink the part and integrate a threaded screw reducing part count and making it easier to install. A strain relief is built in for the flying lead which makes the overall package very robust.
We also transitioned from a platinum sensing element which has a TCR of 3850ppm/C to a low-cost, iron based wire which has a TCR of 3500ppm/C.
Riedon is the largest precision wirewound manufacturer in the world. We have the expertise to solve your most difficult problems.
High Temperature Resistors
Riedon has been at the cutting edge of resistive solutions for more than 40 years. High temperature resistors are in demand in many applications, now more than ever!
Riedon’s Wirewound, Thick & Thin Film, and also Foil resistive products can be seen in industries as diverse as: Aerospace, Military, Instrumentation, and Medical Devices. Here is the list of our “high temperature” resistors:
CHR Series – Non Magnetic Chip Resistors
(-55°C to +155°C – Standard)
(-55°C to +300°C – HT Version)
HVS Series – High Resistance – Thick Film Chip Resistors
(-55°C to +155°C to 250°C upon request)
Wirewound HT Type S and SL – Surface Mount Power Resistors
(-55°C to +275°C)
UT Series – Silicone Coated Power Resistors
(-55°C to +250°C) and (-55°C to +350°C)
100 Series, SM Series, PC Series – Precision Wirewound Resistors
(-55°C to +145°C)
Please call us at Riedon to get more information: +1 (626) 284-9901 (M-F, 6am-5pm PST)
Surge Protected Resistors or Pulse proof resistors
One of the most frequently asked questions that we receive at Riedon, is whether we can offer “Joule rated” or “pulse rated” resistors? Electrical surges are a common failure mode for many types of resistors, and its essential to help our customers to evaluate the best possible surge protected resistor before specifying it for a particular application.
Attached, please find a technical write up addressing this important issue – you can also find it on our website here:
Please review and let me know if you have any questions.
check our surface mount wirewound resistors that can be joule rated here
Also we have the axial wirewound resistors that can be Joule rated - click here
pulse proof resistors or surge resistor.